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A261411
a(1)=1; thereafter a(n) = smallest prime factor of A261570(n).
2
1, 11, 3, 11, 41, 3, 239, 11, 3, 11, 11, 3, 11, 11, 3, 11, 11, 3, 71, 21557, 19, 17, 31, 181, 17, 353, 19, 31, 19, 29, 17, 29, 11616377, 214141, 19, 5471, 17, 13883, 3, 7, 421219193, 3, 17, 7, 3, 7, 101, 3, 634324033999, 13, 19, 13, 83, 13, 23, 13, 19, 13, 19
OFFSET
1,2
LINKS
David Broadhurst and Hiroaki Yamanouchi, Table of n, a(n) for n = 1..99 (First 61 terms from Hiroaki Yamanouchi)
EXAMPLE
A261570(11) = 12345678911987654321 = (11)(59)(34631)(43117)(6373)(1999), so a(10) = 11.
Note that a(2007) = A261570(2007) is a 21233-digit (probable) prime.
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Aug 24 2015, based on Robert G. Wilson v's comment in A261570.
EXTENSIONS
a(41)-a(59) from Hiroaki Yamanouchi, Aug 24 2015
STATUS
approved