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A176974
First exponent n to generate maximum remainder when (a + 1)^n + (a - 1)^n is divided by a^2 for variable n and a>2.
1
1, 1, 7, 5, 3, 3, 13, 9, 5, 5, 19, 13, 7, 7, 25, 17, 9, 9, 31, 21, 11, 11, 37, 25, 13, 13, 43, 29, 15, 15, 49, 33, 17, 17, 55, 37, 19, 19, 61, 41, 21, 21, 67, 45, 23, 23, 73, 49, 25, 25, 79, 53, 27, 27, 85, 57, 29, 29, 91, 61, 31, 31, 97, 65, 33, 33, 103, 69
OFFSET
3,3
FORMULA
From Colin Barker, Oct 29 2017: (Start)
G.f.: x^3*(1 + x + 7*x^2 + 5*x^3 + x^4 + x^5 - x^6 - x^7) / ((1 - x)^2*(1 + x)^2*(1 + x^2)^2).
a(n) = 2*a(n-4) - a(n-8) for n>10.
(End)
PROG
(PARI) Vec(x^3*(1 + x + 7*x^2 + 5*x^3 + x^4 + x^5 - x^6 - x^7) / ((1 - x)^2*(1 + x)^2*(1 + x^2)^2) + O(x^100)) \\ Colin Barker, Oct 29 2017
CROSSREFS
Cf. A159469.
Sequence in context: A335985 A093824 A203142 * A198983 A019935 A255646
KEYWORD
nonn,easy
AUTHOR
Thomas Quirk, Apr 29 2010
EXTENSIONS
Corrected and extended by Ray Chandler, Oct 16 2011
STATUS
approved