A074513 a(n) = 1^n + 4^n + 7^n.

3, 12, 66, 408, 2658, 17832, 121746, 839928, 5830338, 40615752, 283523826, 1981521048, 13858064418, 96956119272, 678491508306, 4748635251768, 33237225536898, 232647693856392, 1628482317387186, 11399170063280088

Offset

0,1

Links

Table of n, a(n) for n=0..19.

Index entries for linear recurrences with constant coefficients, signature (12,-39,28).

Formula

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

G.f.: 1/(1-x) + 1/(1-4*x) + 1/(1-7*x).

E.g.f.: e^x + e^(4*x) + e^(7*x). (End)

a(n) = 11*a(n-1) - 28*a(n-2) + 18 with a(0)=3, a(1)=12. - Vincenzo Librandi, Jul 21 2010

a(0)=3, a(1)=12, a(2)=66, a(n) = 12*a(n-1) - 39*a(n-2) + 28*a(n-3). - Harvey P. Dale, Mar 06 2013

Mathematica

Table[1^n + 4^n + 7^n, {n, 0, 20}]
LinearRecurrence[{12, -39, 28}, {3, 12, 66}, 30] (* Harvey P. Dale, Mar 06 2013 *)

Crossrefs

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

Sequence in context: A183273 A082987 A086836 * A290147 A007871 A214565

Adjacent sequences: A074510 A074511 A074512 * A074514 A074515 A074516

Keyword

easy,nonn

Author

Robert G. Wilson v, Aug 23 2002

Status

approved