Search: id:A130754 Results 1-1 of 1 results found. %I A130754 %S A130754 1,2,2,2,2,6,2,4,6,2,10,20,2,6,15,20,2,14,42,70,2,8,28,56,70,2,18,72, %T A130754 168,252,2,10,45,120,210,252,2,22,110,330,660,924,2,12,66,220,495,792, %U A130754 924,2,26,156,572,1430,2574,3432,2,14,91,364,1001,2002,3003,3432,2,30 %N A130754 A folded back triangular sequence of the binomial / Pascal's triangle A007318: half of the sequence is taken and doubled except for the odd middle terms which remain the same. %C A130754 This fold back operation leaves the row sums at 2^n. %F A130754 a(n,i)== If[n > 0 && i == 0, 2, If[Mod[n, 2] == 0, binomial[n, i], 2*binomial[n, i]]]; %e A130754 {1}, %e A130754 {2}, %e A130754 {2, 2}, %e A130754 {2, 6}, %e A130754 {2, 4, 6}, %e A130754 {2, 10, 20}, %e A130754 {2, 6, 15, 20}, %e A130754 {2, 14, 42, 70}, %e A130754 {2, 8, 28, 56, 70}, %e A130754 {2, 18, 72, 168, 252}, %e A130754 {2, 10, 45, 120, 210, 252} %t A130754 f[n_, i_] = If[n > 0 && i == 0, 2, If[Mod[n, 2] == 0, Binomial[n, i], 2*Binomial[n, i]]]; Table[Table[f[n, i], {i, 0, Floor[n/2]}], {n, 0, 20}]; Flatten[%] %Y A130754 Cf. A007318. %Y A130754 Sequence in context: A073124 A070877 A156717 this_sequence A164126 A163368 A151948 %Y A130754 Adjacent sequences: A130751 A130752 A130753 this_sequence A130755 A130756 A130757 %K A130754 nonn,tabf %O A130754 1,2 %A A130754 Roger L. Bagula (rlbagulatftn(AT)yahoo.com), Jul 13 2007 Search completed in 0.001 seconds