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

Author

Clark Kimberling

Keywords

• nonn
• easy

Links

• 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).

Crossrefs

Cf. A006131, A026581 (first differences).

Programs

Mathematica

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

Formula

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