A054111 Row sums of array T as in A054110.

1, 2, 7, 18, 39, 82, 167, 338, 679, 1362, 2727, 5458, 10919, 21842, 43687, 87378, 174759, 349522, 699047, 1398098, 2796199, 5592402, 11184807, 22369618, 44739239, 89478482, 178956967, 357913938, 715827879, 1431655762

Offset

0,2

Links

Table of n, a(n) for n=0..29.

Index entries for linear recurrences with constant coefficients, signature (2,1,-2)

Formula

G.f.: [1+2x^2+4x^3]/[(1-x^2)(1-2x)]. - Ralf Stephan, Apr 03 2004

a(n+1) = 2^(n+4)/3 -7/2 +(-1)^n/6, n>0. - R. J. Mathar, May 20 2013

a(n) ~ 8*2^n/3. - Charles R Greathouse IV, Jun 02 2026

Prog

(PARI) a(n)=if(n, (16*2^n-21-(-1)^n)/6, 1) \\ Charles R Greathouse IV, Jun 02 2026

Crossrefs

Cf. A054110.

Sequence in context: A393347 A229183 A051743 * A295054 A192955 A055503

Adjacent sequences: A054108 A054109 A054110 * A054112 A054113 A054114

Keyword

nonn,easy

Author

Clark Kimberling

Status

approved