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A017079
a(n) = (8*n + 1)^3.
1
1, 729, 4913, 15625, 35937, 68921, 117649, 185193, 274625, 389017, 531441, 704969, 912673, 1157625, 1442897, 1771561, 2146689, 2571353, 3048625, 3581577, 4173281, 4826809, 5545233, 6331625, 7189057
OFFSET
0,2
FORMULA
G.f.: (1 + 725*x + 2003*x^2 + 343*x^3)/(x-1)^4. - R. J. Mathar, Jul 14 2016
Sum_{n>=0} 1/a(n) = -psi''(1/8)/1024 = 1.0017122... - R. J. Mathar, May 07 2024
MATHEMATICA
Table[(8n+1)^3, {n, 0, 30}] (* or *) LinearRecurrence[{4, -6, 4, -1}, {1, 729, 4913, 15625}, 30] (* Harvey P. Dale, Sep 04 2024 *)
PROG
(Magma) [(8*n+1)^3: n in [0..40]]; // Vincenzo Librandi, Jul 11 2011
CROSSREFS
Sequence in context: A236334 A232286 A219133 * A062556 A017163 A233159
KEYWORD
nonn,easy
STATUS
approved