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 A109409 #6 Mar 31 2012 20:17:50
%S A109409 1,1,1,0,1,1,0,0,1,1,0,0,0,1,1,0,0,0,9,10,1,0,0,0,0,9,10,1,0,0,0,0,0,
%T A109409 9,10,1,0,0,0,0,0,135,159,25,1,0,0,0,0,0,0,135,159,25,1,0,0,0,0,0,0,0,
%U A109409 135,159,25,1,0,0,0,0,0,0,0,2835,3474,684,46,1
%N A109409 Coefficients of polynomials triangular sequence produced by removing primes from the odd numbers in A028338.
%C A109409 The row sums also appear to be new: b = Flatten[Join[{{1}}, Table[Apply[Plus, Abs[CoefficientList[Product[x + g[n], {n, 0, m}], x]]], {m, 0, 10}]]] {1, 2, 2, 2, 2, 20, 20, 20, 320, 320, 320, 7040} Since the row sum of A028338 is the double factorial A000165: this result seems to be a factorization of the double factorial numbers by relatively sparse nonprime odd numbers. It might be better to reverse the order of the coefficients to get the higher powers first.
%F A109409 p[n]=Product[If[PrimeQ[2*n+1]==false,x+(2*n+1),x] a(n) =CoefficientList[p[n],x]
%e A109409 {1},
%e A109409 {1, 1},
%e A109409 {0, 1, 1},
%e A109409 {0, 0, 1, 1},
%e A109409 {0, 0, 0, 1, 1},
%e A109409 {0, 0, 0, 9, 10, 1},
%e A109409 {0, 0, 0, 0, 9, 10, 1},
%e A109409 {0, 0, 0, 0, 0, 9, 10, 1}
%t A109409 a = Join[{{1}}, Table[CoefficientList[Product[x + g[n], {n, 0, m}], x], {m, 0, 10}]]; Flatten[a]
%Y A109409 Cf. A028338, A000165, A039757.
%K A109409 nonn,uned
%O A109409 1,19
%A A109409 _Roger L. Bagula_, May 19 2007