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 A112883 #11 Jan 26 2020 20:11:30 %S A112883 1,0,1,0,1,3,0,0,2,5,0,0,1,7,11,0,0,0,3,16,21,0,0,0,1,12,41,43,0,0,0, %T A112883 0,4,34,94,85,0,0,0,0,1,18,99,219,171,0,0,0,0,0,5,60,261,492,341,0,0, %U A112883 0,0,0,1,25,195,678,1101,683,0,0,0,0,0,0,6,95,576,1692,2426,1365,0,0,0,0,0 %N A112883 A skew Jacobsthal-Pascal matrix. %C A112883 T(n,n) is A001045(n), row sums are A006130, column sums are A002605. Compare with [0,1,-1,0,0,..] DELTA [1,2,-2,0,0,...] where DELTA is the operator defined in A084938. A skewed version of the Riordan array (1/(1-x-2x^2),x/(1-x-2x^2)) (A073370). %C A112883 Modulo 2, this sequence gives A106344. - _Philippe Deléham_, Dec 18 2008 %F A112883 From _Philippe Deléham_: (Start) %F A112883 G.f.: 1/(1-yx(1-x)-2x^2*y*2); %F A112883 Number triangle T(n, k) = Sum_{j=0..2k-n} C(n-k+j, n-k)*C(j, 2k-n-j)*2^(2k-n-j); %F A112883 T(n, k) = A073370(k, n-k); T(n, k) = T(n-1, k-1) + T(n-2, k-1) + 2*T(n-2, k-2). (End) %e A112883 Rows begin %e A112883 1; %e A112883 0, 1; %e A112883 0, 1, 3; %e A112883 0, 0, 2, 5; %e A112883 0, 0, 1, 7, 11; %e A112883 0, 0, 0, 3, 16, 21; %e A112883 0, 0, 0, 1, 12, 41, 43; %e A112883 0, 0, 0, 0, 4, 34, 94, 85; %e A112883 0, 0, 0, 0, 1, 18, 99, 219, 171; %e A112883 0, 0, 0, 0, 0, 5, 60, 261, 492, 341; %e A112883 0, 0, 0, 0, 0, 1, 25, 195, 678, 1101, 683; %Y A112883 Cf. A111006. %K A112883 easy,nonn,tabl %O A112883 0,6 %A A112883 _Paul Barry_, Oct 05 2005