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A220989
a(n) = 12^(2n+1) - 6 * 12^n + 1: the left Aurifeuillian factor of 12^(6n+3) + 1.
2
7, 1657, 247969, 35821441, 5159655937, 743006877697, 106993187463169, 15407021359595521, 2218611104160546817, 319479999339664244737, 46005119908998197280769, 6624737266944778960896001, 953962166440636632998608897
OFFSET
0,1
COMMENTS
The corresponding right Aurifeuillian factor is A220990.
FORMULA
Aurifeuillian factorization: 12^(6n+3) + 1 = (12^(2n+1) + 1) * a(n) * A220990(n).
G.f.: -(1008*x^2+558*x+7) / ((x-1)*(12*x-1)*(144*x-1)). [Colin Barker, Jan 03 2013]
MATHEMATICA
Table[12^(2n+1) - 6 * 12^n + 1, {n, 0, 20}]
KEYWORD
nonn,easy
AUTHOR
Stuart Clary, Dec 27 2012
STATUS
approved