OFFSET
0,1
COMMENTS
7th cyclotomic polynomial evaluated at powers of 2.
LINKS
T. D. Noe, Table of n, a(n) for n = 0..200
FORMULA
G.f.: (-7+762 x-26670 x^2+377952 x^3-2267712 x^4+5462016 x^5-4161536 x^6)/(-1+127 x-5334 x^2+94488 x^3-755904 x^4+2731008 x^5-4161536 x^6+2097152 x^7). - Harvey P. Dale, Mar 21 2011
a(n) = (2^(7*n) - 1)/( 2^n - 1). Exp( Sum_{n >= 1} a(n)*x^n/n ) = 1 + 127*x + 10795*x^2 + ... is the o.g.f. for the 6th subdiagonal of triangle A022166, essentially A022189. - Peter Bala, Apr 07 2015
MAPLE
with(numtheory, cyclotomic):seq(cyclotomic(7, 2^i), i=0..24);
MATHEMATICA
Total[#^Range[0, 15]&/@Divisors[64]] (* Harvey P. Dale, Mar 21 2011 *)
PROG
(Magma) [&+[Divisors(64)[i]^n: i in [1..7]]: n in [0..15]]; // Vincenzo Librandi, Apr 17 2014
(PARI) a(n) = polcyclo(7, 2^n); \\ Michel Marcus, Nov 13 2016
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved