A302942 a(n) = (2^n-1)^2*(2^n + 2).

0, 4, 54, 490, 4050, 32674, 261954, 2096770, 16776450, 134216194, 1073738754, 8589928450, 68719464450, 549755789314, 4398046461954, 35184371990530, 281474976514050, 2251799813292034, 18014398508695554, 144115188074283010, 1152921504603701250, 9223372036848484354

Offset

0,2

Comments

a(n) is also the number of total dominating sets in the complete tripartite graph K_{n,n,n} for n > 0.

Links

Table of n, a(n) for n=0..21.

Eric Weisstein's World of Mathematics, Complete Tripartite Graph

Eric Weisstein's World of Mathematics, Total Dominating Set

Index entries for linear recurrences with constant coefficients, signature (11,-26,16).

Formula

a(n) = A291703(n) for n > 1.

a(n) = 11*a(n-1) - 26*a(n-2) + 16*a(n-3).

G.f.: -2*x*(2 + 5*x)/(-1 + 11*x - 26*x^2 + 16*x^3).

Mathematica

Table[(2^n - 1)^2 (2^n + 2), {n, 0, 30}]
LinearRecurrence[{11, -26, 16}, {4, 54, 490}, {0, 20}]
CoefficientList[Series[-((2 x (2 + 5 x))/(-1 + 11 x - 26 x^2 + 16 x^3)), {x, 0, 20}], x]

Crossrefs

Cf. A291703.

Sequence in context: A001545 A208954 A269507 * A292305 A073863 A269480

Adjacent sequences: A302939 A302940 A302941 * A302943 A302944 A302945

Keyword

nonn

Author

Eric W. Weisstein, Apr 16 2018

Status

approved