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 A083075 #13 Sep 09 2018 02:29:17 %S A083075 1,1,1,1,3,1,1,5,13,1,1,7,33,63,1,1,9,61,229,313,1,1,11,97,547,1601, %T A083075 1563,1,1,13,141,1065,4921,11205,7813,1,1,15,193,1831,11713,44287, %U A083075 78433,39063,1,1,17,253,2893,23801,128841,398581,549029,195313,1,1,19,321 %N A083075 Square array read by antidiagonals: T(n,k) = (k*(2*k+3)^n + 1)/(k+1). %H A083075 Nathaniel Johnston, <a href="/A083075/b083075.txt">Antidiagonals 0..100, flattened</a> %e A083075 Array begins: %e A083075 1 1 1 1 1 ... %e A083075 1 3 13 63 313 ... %e A083075 1 5 33 229 1601 ... %e A083075 1 7 61 547 4921 ... %e A083075 1 9 97 1065 11713 ... %e A083075 ... %p A083075 T := proc(n,k) return (k*(2*k+3)^n+1)/(k+1): end: seq(seq(T(k,n-k),k=0..n),n=0..10); # _Nathaniel Johnston_, Jun 26 2011 %Y A083075 Rows include A034478, A083076, A066443, A083077, A083078. %Y A083075 Columns include odds, A082109, A083079. %Y A083075 Diagonals include A083079, A083080, A083081, A083082. %K A083075 easy,nonn,tabl %O A083075 0,5 %A A083075 _Paul Barry_, Apr 23 2003