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A220986 The right Aurifeuillian factor of 10^(20n + 10) + 1. 1
27961, 1105207205101, 101005020070200501001, 10010005002000700200050010001, 1000100005000200007000200005000100001, 100001000005000020000070000200000500001000001, 10000010000005000002000000700000200000050000010000001 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

The corresponding left Aurifeuillian factor is A220985.

LINKS

Table of n, a(n) for n=0..6.

Wikipedia, Cunningham Project

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) * A220985(n) * a(n)

MATHEMATICA

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

CROSSREFS

Cf. A092440, A085601, A220978, A198410, A220979, A220980, A220981, A220982

Cf. A220983, A220984, A220985, A220987, A220988, A220989, A220990

Sequence in context: A202403 A206618 A233430 * A242607 A203658 A247992

Adjacent sequences:  A220983 A220984 A220985 * A220987 A220988 A220989

KEYWORD

nonn,easy

AUTHOR

Stuart Clary, Dec 27 2012

STATUS

approved

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Last modified August 9 10:34 EDT 2022. Contains 356021 sequences. (Running on oeis4.)