A074522 a(n) = 1^n + 6^n + 9^n.

3, 16, 118, 946, 7858, 66826, 578098, 5062906, 44726338, 397498186, 3547250578, 31743856666, 284606318818, 2554926522346, 22955156619058, 206361317079226, 1855841298759298, 16694108359111306, 150196195253667538

Offset

0,1

Links

Table of n, a(n) for n=0..18.

Index entries for linear recurrences with constant coefficients, signature (16,-69,54).

Formula

From Mohammad K. Azarian, Dec 26 2008: (Start)

G.f.: 1/(1-x) + 1/(1-6*x) + 1/(1-9*x).

E.g.f.: e^x + e^(6*x) + e^(9*x). (End)

a(n) = 15*a(n-1) - 54*a(n-2) + 40 with a(0)=3, a(1)=16. - Vincenzo Librandi, Jul 21 2010

E.g.f.: A(x)=Q(0); Q(k)=1+(6^k)/(1-(3^k)/((2^k)+(3^k)-(2^k)*x/(x+(9^k)*(k+1)/Q(k+1)))); (continued fraction). - Sergei N. Gladkovskii, Nov 26 2011

Mathematica

Table[1^n + 6^n + 9^n, {n, 0, 20}]

Crossrefs

Cf. A001550, A001576, A034513, A001579, A074501..A074580.

Equals A074621 + 1.

Sequence in context: A336293 A355718 A221409 * A302701 A190633 A220352

Adjacent sequences: A074519 A074520 A074521 * A074523 A074524 A074525

Keyword

easy,nonn

Author

Robert G. Wilson v, Aug 23 2002

Status

approved