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A093818
a(n) = gcd(A001008(n), n!).
1
1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 5, 1, 3, 1, 5, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 7, 1, 1, 1, 1, 1, 7, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 11, 1, 1, 11, 1, 1, 1, 11, 1, 1, 11, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1
OFFSET
1,7
COMMENTS
Conjecture: every odd prime occurs as a term in the sequence.
Observation: Terms other than 1 are rare. Of the terms a(1) .. a(29524), only 187 are larger than one. Among these 187 terms, the following 50 distinct values occur: 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 121, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 227, 257, 269, 509, 863, 919, 1049, 1331, 9409, 11881. Of these, all other are primes except 121 = 11*11, 1331 = 11*11*11, 9409 = 97*97 and 11881 = 109*109. - Antti Karttunen, Aug 28 2017
LINKS
PROG
(PARI)
A001008(n) = numerator(sum(i=1, n, 1/i)); \\ This function from Michael B. Porter, Dec 08 2009
A093818(n) = gcd(A001008(n), n!); \\ Antti Karttunen, Aug 28 2017
CROSSREFS
Sequence in context: A370079 A318497 A202150 * A097031 A372565 A354997
KEYWORD
easy,nonn
AUTHOR
Vladeta Jovovic, May 20 2004
EXTENSIONS
More terms from David Wasserman, Apr 20 2007
Name edited (A001008 substituted for "Wolstenholme") by Antti Karttunen, Aug 28 2017
STATUS
approved