%I #14 Jan 05 2024 13:38:03
%S 1,1,2,3,6,15,51,227,1257,8296,63394,549740,5330185,57117590,
%T 670163058,8543228103,117564576721,1736762231296,27411856376831,
%U 460320540171210,8194312180092795,154127845115561811,3054239953905841713,63597989583700047353,1388275729125313815336
%N a(n) = Sum_{j=0..n} Sum_{k=0..j} abs( Stirling1(j - k, k) ).
%H Andrew Howroyd, <a href="/A320963/b320963.txt">Table of n, a(n) for n = 0..200</a>
%p a := n -> add(add(abs(Stirling1(j - k, k)), k=0..j), j=0..n):
%p seq(a(n), n=0..29);
%t a[n_] := Sum[Sum[Abs[StirlingS1[j - k, k]], {k, 0, j}], {j, 0, n}];
%t Array[a, 25, 0] (* _Amiram Eldar_, Nov 06 2018 *)
%o (PARI) a(n)={sum(j=0, n, sum(k=0, j, abs(stirling(j-k, k, 1))))} \\ _Andrew Howroyd_, Nov 06 2018
%Y The Stirling_2 counterpart: A320964.
%K nonn
%O 0,3
%A _Peter Luschny_, Nov 06 2018