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A220985
The left Aurifeuillian factor of 10^(20n+10) + 1.
1
3541, 904806804901, 99004980069800499001, 9990004998000699800049990001, 999900004999800006999800004999900001, 99999000004999980000069999800000499999000001, 9999990000004999998000000699999800000049999990000001
OFFSET
0,1
COMMENTS
The corresponding right Aurifeuillian factor is A220986.
FORMULA
a(n) = 10^(8n+4) - 10^(7n+4) + 5 * 10^(6n+3) - 2 * 10^(5n+3) + 7 * 10^(4n+2) - 2 * 10^(3n+2) + 5 * 10^(2n+1) - 10^(n+1) + 1.
Aurifeuillian factorization: 10^(20n+10) + 1 = (10^(4n+2) + 1) * a(n) * A220986(n).
MATHEMATICA
Table[10^(8n+4) - 10^(7n+4) + 5 * 10^(6n+3) - 2 * 10^(5n+3) + 7 * 10^(4n+2) - 2 * 10^(3n+2) + 5 * 10^(2n+1) - 10^(n+1) + 1, {n, 0, 20}]
KEYWORD
nonn,easy
AUTHOR
Stuart Clary, Dec 27 2012
STATUS
approved