[go: up one dir, main page]

login
A016972
a(n) = (6*n + 5)^4.
9
625, 14641, 83521, 279841, 707281, 1500625, 2825761, 4879681, 7890481, 12117361, 17850625, 25411681, 35153041, 47458321, 62742241, 81450625, 104060401, 131079601, 163047361, 200533921, 244140625, 294499921, 352275361, 418161601, 492884401, 577200625, 671898241
OFFSET
0,1
FORMULA
From _Chai Wah Wu_, Mar 20 2017: (Start)
a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5) for n > 4.
G.f.: (-x^4 - 2396*x^3 - 16566*x^2 - 11516*x - 625)/(x - 1)^5. (End)
From _Amiram Eldar_, Apr 01 2022: (Start)
a(n) = A016969(n)^4 = A016970(n)^2.
Sum_{n>=0} 1/a(n) = PolyGamma(3, 5/6)/7776. (End)
MATHEMATICA
Table[(6 n + 5)^4, {n, 0, 20}] (* _Michael De Vlieger_, Mar 20 2017 *)
PROG
(Magma) [(6*n+5)^4: n in [0..40]]; // _Vincenzo Librandi_, May 07 2011
CROSSREFS
Subsequence of A000583.
Sequence in context: A250827 A055868 A016852 * A156162 A017044 A080175
KEYWORD
nonn,easy
AUTHOR
_N. J. A. Sloane_
STATUS
approved