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 A112709 #6 Mar 15 2023 11:55:30
%S A112709 1,2,2,5,14,65,376,2613,20761,184756,1816330,19526217,227588213,
%T A112709 2855033988,38311846704,547128228043,8279365967056,132259968568859,
%U A112709 2223048616707842,39199883209336095,723269314782624612
%N A112709 Unsigned row sums of triangle A112707 (partial sums of Catalan numbers multiplied by powers of negative numbers).
%F A112709 a(n) = Sum_{m=0..n} |A112707(n, m)|, for n >= 0.
%Y A112709 Cf. A112707, A112708 (signed row sums).
%K A112709 nonn,easy
%O A112709 0,2
%A A112709 _Wolfdieter Lang_, Oct 31 2005