OFFSET
1,1
LINKS
Harry J. Smith, Table of n, a(n) for n = 1..1000
Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1).
FORMULA
a(n) = 10*n^3 + 7.
G.f.: -x*(-17 - 19*x - 31*x^2 + 7*x^3)/(x-1)^4. - R. J. Mathar, Feb 27 2015
From Elmo R. Oliveira, Aug 18 2025: (Start)
E.g.f.: -7 + exp(x)*(7 + 10*x + 30*x^2 + 10*x^3).
a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4) for n > 4. (End)
EXAMPLE
a(3) = 277 because we can say 10 * 3^3 + 7 = 10 * 27 + 7 = 270 + 7 = 277.
MATHEMATICA
(10 Range[30]^3)+7 (* or *) LinearRecurrence[{4, -6, 4, -1}, {17, 87, 277, 647}, 30] (* Harvey P. Dale, Oct 20 2016 *)
PROG
(PARI) a(n) = { 10*n^3 + 7 } \\ Harry J. Smith, Jul 26 2009
CROSSREFS
KEYWORD
base,easy,nonn
AUTHOR
Terrel Trotter, Jr., Jun 23 2001
STATUS
approved