OFFSET
1,1
LINKS
Colin Barker, Table of n, a(n) for n = 1..1000
Index entries for linear recurrences with constant coefficients, signature (1,16,-16,-1,1).
FORMULA
a(n) = a(n-1)+16*a(n-2)-16*a(n-3)-a(n-4)+a(n-5) for n>5.
G.f.: 14*x*(x^4+4*x^3-13*x^2-32*x-2) / ((x-1)*(x^4-16*x^2+1)).
EXAMPLE
28 is in the sequence because (28+84)^3 - 28^3 = 1176^2.
MATHEMATICA
LinearRecurrence[{1, 16, -16, -1, 1}, {28, 476, 1106, 8218, 18256}, 30] (* Paolo Xausa, Mar 05 2024 *)
PROG
(PARI) Vec(14*x*(x^4+4*x^3-13*x^2-32*x-2)/((x-1)*(x^4-16*x^2+1)) + O(x^40))
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Colin Barker, Oct 30 2015
STATUS
approved