A133572 Row sums of triangle A133571.

1, 4, 6, 16, 24, 64, 96, 256, 384, 1024, 1536, 4096, 6144, 16384, 24576, 65536, 98304, 262144, 393216, 1048576, 1572864, 4194304, 6291456, 16777216, 25165824, 67108864, 100663296, 268435456, 402653184, 1073741824, 1610612736, 4294967296

Offset: 1

Author

Gary W. Adamson, Sep 16 2007

Keywords

• nonn
• easy

Examples

			a(4) = 16 = sum or row 4 terms of triangle A133571: (5 + 5 + 5 + 1).
a(4) = 16 = 2^4.
a(7) = 96 = 2^6 + 2^5 = 64 + 32.
		

Links

• Index entries for linear recurrences with constant coefficients, signature (0, 4).

Crossrefs

Cf. A133571.

Formula

Even-indexed terms, a(n) = 2^n; odd-indexed terms, a(n) = 2^(n-1) + 2^(n-2).

G.f.: -x*(4*x+1+2*x^2)/(2*x-1)/(2*x+1). - R. J. Mathar, Nov 14 2007