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 A049402 #17 Jan 18 2025 09:05:40 %S A049402 1,1,7,61,649,8245,122215,2069425,39328465,827226505,19047582055, %T A049402 475956135205,12815133759385,369605936607805,11361372997850695, %U A049402 370609338222772825,12780705695068446625,464412124831585889425,17729002673226394402375,709180766131239680070925 %N A049402 Row sums of triangle A049374. %H A049402 Alois P. Heinz, <a href="/A049402/b049402.txt">Table of n, a(n) for n = 0..415</a> %H A049402 W. Lang, <a href="http://www.cs.uwaterloo.ca/journals/JIS/index.html">On generalizations of Stirling number triangles</a>, J. Integer Seqs., Vol. 3 (2000), #00.2.4. %F A049402 E.g.f. exp(p(x)) with p(x) := (1-(1-x)^5)/(5*(1-x)^5) (E.g.f. first column of A049374). %F A049402 From _Seiichi Manyama_, Jan 18 2025: (Start) %F A049402 a(n) = Sum_{k=0..n} |Stirling1(n,k)| * A005011(k). %F A049402 a(n) = (1/exp(1/5)) * (-1)^n * n! * Sum_{k>=0} binomial(-5*k,n)/(5^k * k!). (End) %p A049402 a:= proc(n) option remember; `if`(n=0, 1, add( %p A049402 binomial(n-1, j-1)*(j+4)!/5!*a(n-j), j=1..n)) %p A049402 end: %p A049402 seq(a(n), n=0..25); # _Alois P. Heinz_, Aug 01 2017 %t A049402 a[0] = 1; a[n_] := a[n] = Sum[Binomial[n - 1, j - 1]*(j + 4)!/5!*a[n - j], {j, 1, n}]; %t A049402 Table[a[n], {n, 0, 25}] (* _Jean-François Alcover_, Jun 04 2018, after _Alois P. Heinz_ *) %Y A049402 Column k=6 of A291709. %Y A049402 Cf. A049374, A049427. %K A049402 easy,nonn %O A049402 0,3 %A A049402 _Wolfdieter Lang_ %E A049402 a(0)=1 prepended by _Alois P. Heinz_, Aug 01 2017