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A059839
a(n) = n^8 + n^6 + n^4 + n^2 + 1.
5
1, 5, 341, 7381, 69905, 406901, 1727605, 5884901, 17043521, 43584805, 101010101, 216145205, 432988561, 820586261, 1483357205, 2574332101, 4311810305, 6999978821, 11054078101, 17030739605, 25664160401, 37908820405, 54989488181
OFFSET
0,2
LINKS
FORMULA
a(n) = (n^4-n^3+n^2-n+1)*(n^4+n^3+n^2+n+1) = A060884(n)*A053699(n). a(n) = (n^10-1)/(n^2-1), n>1. - Alexander Adamchuk, Apr 13 2006
G.f.: -(5*x^8 +296*x^7 +4492*x^6 +15332*x^5 +15458*x^4 +4408*x^3 +332*x^2 -4*x +1)/ (x-1)^9. - Colin Barker, Nov 05 2012
MATHEMATICA
Table[Total[n^(2*Range[4])]+1, {n, 0, 30}] (* or *) LinearRecurrence[{9, -36, 84, -126, 126, -84, 36, -9, 1}, {1, 5, 341, 7381, 69905, 406901, 1727605, 5884901, 17043521}, 30] (* Harvey P. Dale, Jan 02 2015 *)
PROG
(PARI) { for (n=0, 1000, f=n^2; write("b059839.txt", n, " ", f^4 + f^3 + f^2 + f + 1); ) } \\ Harry J. Smith, Jun 29 2009
CROSSREFS
Cf. A059830.
Sequence in context: A265921 A203684 A124477 * A300388 A269556 A227448
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Feb 25 2001
STATUS
approved