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 A081958 #20 Jan 18 2021 03:09:45 %S A081958 2,8,36,180,1080,7560,60480,524160,5241600,56609280,670602240, %T A081958 8622028800,118879488000,1793381990400,28158588057600,474249904128000, %U A081958 8447576417280000,159659194286592000,3162772610629632000,66117689869271040000,1445143792856924160000 %N A081958 Diagonal of A081957. %H A081958 James Rayman, <a href="/A081958/b081958.txt">Table of n, a(n) for n = 1..400</a> %o A081958 (Python) def a(n): return row(n)[-1] # row(n) is given in A081957. - _James Rayman_, Jan 17 2021 %Y A081958 Cf. A081957, A081959, A081960. %K A081958 nonn %O A081958 1,1 %A A081958 _Amarnath Murthy_, Apr 02 2003 %E A081958 Corrected and extended by Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Apr 08 2003 %E A081958 a(11)-a(19) from _James Rayman_, Jan 16 2021 %E A081958 Corrected and extended by _James Rayman_, Jan 17 2021