This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A006136 M5206 #22 Jul 08 2025 16:41:50
%S A006136 1,29,626,13869,347020,9952274,321541977,11416400590,435869304863,
%T A006136 17605464402686,743624059688891,32572923621373010,1470621027107356485,
%U A006136 68120063089374617281,3225635202844511176442,155695310201341829770911
%N A006136 T(n+3,3) from table A045912 of characteristic polynomial of negative Pascal matrix.
%D A006136 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H A006136 W. F. Lunnon, <a href="https://web.archive.org/web/2024*/https://www.fq.math.ca/Scanned/15-3/lunnon.pdf">The Pascal matrix</a>, Fib. Quart. vol. 15 (1977) pp. 201-204.
%e A006136 1 + 29*x + 626*x^2 + 13869*x^3 + 347020*x^4 + 9952274*x^5 + 321541977*x^6 + ...
%o A006136 (PARI) {a(n) = if( n<0, 0, polcoeff( charpoly( matrix( n+3, n+3, i, j, -binomial( i+j-2, i-1))), 3))} /* _Michael Somos_, Jul 10 2002 */
%Y A006136 Cf. A045912, A006134, A006135.
%K A006136 nonn
%O A006136 0,2
%A A006136 _N. J. A. Sloane_
%E A006136 Edited by _Michael Somos_, Jul 19 2002