A055374 Invert transform applied three times to Pascal's triangle A007318.

1, 1, 1, 4, 8, 4, 16, 48, 48, 16, 64, 256, 384, 256, 64, 256, 1280, 2560, 2560, 1280, 256, 1024, 6144, 15360, 20480, 15360, 6144, 1024, 4096, 28672, 86016, 143360, 143360, 86016, 28672, 4096, 16384, 131072, 458752, 917504, 1146880, 917504

Offset: 0

Author

Christian G. Bower, May 16 2000

Keywords

• nonn
• tabl
• easy

Comments

Triangle T(n,k), 0 <= k <= n, read by rows, given by [1, 3, 0, 0, 0, 0, 0, 0, 0, ...] DELTA [1, 3, 0, 0, 0, 0, 0, 0, 0, ...] where DELTA is the operator defined in A084938. - Philippe Deléham, Aug 10 2005

Examples

			   1;
   1,   1;
   4,   8,   4;
  16,  48,  48,  16;
  64, 256, 384, 256, 64; ...
		

Links

• N. J. A. Sloane, Transforms
• Index entries for triangles and arrays related to Pascal's triangle

Crossrefs

Cf. A000302, A007318, A055372, A055373.

Formula

a(n,k) = 4^(n-1)*C(n, k), for n>0.

G.f.: (-1+3*x+3*x*y)/(-1+4*x+4*x*y). - R. J. Mathar, Aug 12 2015