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 A054106 #7 May 10 2013 12:44:26
%S A054106 1,1,1,1,1,1,1,2,2,1,1,3,5,3,1,1,4,8,8,4,1,1,5,12,15,12,5,1,1,6,17,27,
%T A054106 27,17,6,1,1,7,23,44,55,44,23,7,1,1,8,30,67,99,99,67,30,8,1,1,9,38,97,
%U A054106 166,197,166,97,38,9,1,1,10,47,135,263,363,363
%N A054106 Alternating sums of vertically aligned numbers in Pascal's triangle: T(n,k) = C(n,k) - C(n-2,k-1) + C(n-4,k-2) - ... +- C(n-2[n/2],m).
%F A054106 G.f.: 1/(1-(1+y)*x)/(1+y*x^2). - _Vladeta Jovovic_, Oct 12 2003
%e A054106 Rows: {1}; {1,1}; {1,1,1}; {1,2,2,1}; {1,3,5,3,1} ...
%Y A054106 For (nonalternating) vertically aligned sums, see A013580.
%Y A054106 Row sums of this array: A007910.
%K A054106 nonn,tabl
%O A054106 0,8
%A A054106 _Clark Kimberling_