OFFSET
1,2
COMMENTS
This fold back operation leaves the row sums at 2^n.
FORMULA
a(n,i)== If[n > 0 && i == 0, 2, If[Mod[n, 2] == 0, binomial[n, i], 2*binomial[n, i]]];
EXAMPLE
{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, 168, 252},
{2, 10, 45, 120, 210, 252}
MATHEMATICA
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[%]
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
Roger L. Bagula, Jul 13 2007
STATUS
approved