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 A136661 #13 Sep 26 2024 03:27:32 %S A136661 1,30,645,12495,235305,4452840,86070600,1713927600,35318883600, %T A136661 754896542400,16751853518400,386036370720000,9235831629024000, %U A136661 229285008336384000,5902321642753536000,157423965566579712000 %N A136661 Unsigned fifth column (k=4) of triangle A136656 divided by 16. %C A136661 Also unsigned fourth column of triangle A136657 divided by 8. %D A136661 Ch. A. Charalambides, Enumerative Combinatorics, Chapman & Hall/CRC, Boca Raton, Florida, 2002, Table 8.3, p. 311, with s=-2, k=4 column/16. %F A136661 a(n) = |A136656(n+4,4)|/16, n>=0. %F A136661 E.g.f.: (8+144*x+228*x^2-220*x^3-45*x^4+60*x^5-10*x^6)/(8*(1-x)^12) (derived from the one given for the column k=4 under A136656). %Y A136661 Cf. A136656, A136660 (column k=3). %K A136661 nonn,easy %O A136661 0,2 %A A136661 _Wolfdieter Lang_, Feb 22 2008