

A117619


a(n) = n^2 + 7.


10



7, 8, 11, 16, 23, 32, 43, 56, 71, 88, 107, 128, 151, 176, 203, 232, 263, 296, 331, 368, 407, 448, 491, 536, 583, 632, 683, 736, 791, 848, 907, 968, 1031, 1096, 1163, 1232, 1303, 1376, 1451, 1528, 1607, 1688, 1771, 1856, 1943, 2032, 2123, 2216, 2311, 2408
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OFFSET

0,1


LINKS

Ivan Panchenko, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (3,3,1).


FORMULA

G.f.: (8*x^2 + 13*x  7)/(x  1)^3.  Indranil Ghosh, Apr 05 2017
From Amiram Eldar, Nov 02 2020: (Start)
Sum_{n>=0} 1/a(n) = (1 + sqrt(7)*Pi*coth(sqrt(7)*Pi))/14.
Sum_{n>=0} (1)^n/a(n) = (1 + sqrt(7)*Pi*cosech(sqrt(7)*Pi))/14. (End)


MATHEMATICA

Table[n^2 + 7, {n, 0, 60}] (* Stefan Steinerberger, Apr 08 2006 *)


PROG

(PARI) a(n) = n^2 + 7 \\ Indranil Ghosh, Apr 05 2017
(Python) def a(n): return n**2 + 7 # Indranil Ghosh, Apr 05 2017


CROSSREFS

Cf. A117951, A117950.
Sequence in context: A090385 A145826 A102963 * A226977 A098731 A294483
Adjacent sequences: A117616 A117617 A117618 * A117620 A117621 A117622


KEYWORD

nonn,less,easy


AUTHOR

Parthasarathy Nambi, Apr 07 2006


EXTENSIONS

More terms from Stefan Steinerberger, Apr 08 2006


STATUS

approved



