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A017116
a(n) = (8*n + 4)^4.
1
256, 20736, 160000, 614656, 1679616, 3748096, 7311616, 12960000, 21381376, 33362176, 49787136, 71639296, 100000000, 136048896, 181063936, 236421376, 303595776, 384160000, 479785216, 592240896, 723394816, 875213056, 1049760000, 1249198336, 1475789056, 1731891456
OFFSET
0,1
FORMULA
G.f.: -256*(1 + 76*x + 230*x^2 + 76*x^3 + x^4)/(x-1)^5. - R. J. Mathar, May 08 2015
From Amiram Eldar, Apr 25 2023: (Start)
a(n) = A017113(n)^4.
a(n) = 2^4*A016828(n) = 2^8*A016756(n).
Sum_{n>=0} 1/a(n) = Pi^4/24576. (End)
MATHEMATICA
(8*Range[0, 20]+4)^4 (* or *) LinearRecurrence[{5, -10, 10, -5, 1}, {256, 20736, 160000, 614656, 1679616}, 20] (* Harvey P. Dale, Aug 05 2019 *)
PROG
(Magma) [(8*n+4)^4: n in [0..35] ]; // Vincenzo Librandi, Jul 21 2011
CROSSREFS
KEYWORD
nonn,easy
STATUS
approved