A026583 a(n) = Sum{T(i,j)}, 0<=j<=i, 0<=i<=2n, T given by A026568.

1, 4, 11, 30, 77, 200, 511, 1314, 3361, 8620, 22067, 56550, 144821, 371024, 950311, 2434410, 6235657, 15973300, 40915931, 104809134, 268472861, 687709400, 1761600847, 4512438450, 11558841841, 29608595644, 75843963011

Offset

0,2

Links

Table of n, a(n) for n=0..26.

Amir Sapir, The Tower of Hanoi with Forbidden Moves, The Computer J. 47 (1) (2004) 20, case cyclic++, sequence d(n) (offset 1).

Index entries for linear recurrences with constant coefficients, signature (2,3,-4).

Formula

G.f.: (1+2x)/[(1-x)(1-x-4x^2)]. - Ralf Stephan, Feb 04 2004 (follows from first comment in A026581)

Mathematica

LinearRecurrence[{2, 3, -4}, {1, 4, 11}, 40] (* Harvey P. Dale, Apr 03 2024 *)

Crossrefs

Cf. A006131, A026581 (first differences).

Sequence in context: A296262 A102281 A269083 * A339739 A291238 A110034

Adjacent sequences: A026580 A026581 A026582 * A026584 A026585 A026586

Keyword

nonn,easy

Author

Clark Kimberling

Status

approved