The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for the OEIS

(Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A399100

Triangle read by rows: T(n,k) is the number of simple connected graphs on n nodes with longest induced path having k nodes.
(history; published version)

#7 by Michael De Vlieger at Tue Aug 25 20:30:55 EDT 2026

STATUS

proposed

approved

A399298

allocated for Alper Ferudun
(history; published version)

#5 by Alper Ferudun at Tue Aug 25 20:26:27 EDT 2026

STATUS

editing

proposed

A398141

allocated for Jwalin Bhatt
(history; published version)

#30 by Jwalin Bhatt at Tue Aug 25 20:26:15 EDT 2026

STATUS

editing

proposed

#29 by Jwalin Bhatt at Tue Aug 25 20:24:35 EDT 2026

COMMENTS

Conjecture: every term after 0 is either the numerator of a convergent (A096456) or semiconvergent of Pi/2, or else p + 2p', where p/q and p'/q' are consecutive convergents of Pi/2. Of the 13 terms after 0, 7 are convergents, 4 are semiconvergents, and 2 are of the last form: 364863 = 260515 + 2*52174 and 5992555 = 4846147 + 2*573204.

CROSSREFS

Cf. A096456, A382815, A383229, A383540, A399200.

Discussion

Tue Aug 25

20:24

Jwalin Bhatt: Similar to my other draft: A399200.

A399100

Triangle read by rows: T(n,k) is the number of simple connected graphs on n nodes with longest induced path having k nodes.
(history; published version)

#6 by Andrew Howroyd at Tue Aug 25 20:24:33 EDT 2026

STATUS

editing

proposed

A399298

allocated for Alper Ferudun
(history; published version)

#4 by Alper Ferudun at Tue Aug 25 20:24:32 EDT 2026

LINKS

Alper Ferudun, <a href="/A399298/a399298.cpp.txt">C++ program for computing the sequence</a>

A397239

allocated for Nickolas James Hahn
(history; published version)

#47 by Nickolas James Hahn at Tue Aug 25 20:22:48 EDT 2026

STATUS

editing

proposed

A399100

Triangle read by rows: T(n,k) is the number of simple connected graphs on n nodes with longest induced path having k nodes.
(history; published version)

#5 by Andrew Howroyd at Tue Aug 25 20:22:30 EDT 2026

NAME

Triangle read by rows: T(n,k) is the number of simple connected graphs on n nodes with longest induced path having k nodes, 1 <= k <= n.

A397239

allocated for Nickolas James Hahn
(history; published version)

#46 by Nickolas James Hahn at Tue Aug 25 20:22:15 EDT 2026

REFERENCES

W. G. Spohn, On the integral cuboid, Amer. Math. Monthly, 79 (1972), 57-59.

PROG

python

(Python)

Discussion

Tue Aug 25

20:22

Nickolas James Hahn: Thank you, Sean. Updated:
1. Program language header changed to (Python).
2. References sorted alphabetically by author surname (Rathbun, then Spohn).

A399100

Triangle read by rows: T(n,k) is the number of simple connected graphs on n nodes with longest induced path having k nodes.
(history; published version)

#4 by Andrew Howroyd at Tue Aug 25 20:20:33 EDT 2026

LINKS

Wikipedia, <a href="https://en.wikipedia.org/wiki/Induced_path">Induced path</a>.

Showing entries 1-10 | older changes