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A119657 Denominator of BernoulliB[10p] divided by 66, where p=Prime[n]. 1
5, 217, 1, 71, 23, 131, 1, 191, 47, 59, 311, 1, 83, 431, 1, 107, 1, 1, 1, 1, 1, 1, 167, 179, 971, 1, 1031, 1, 1091, 227, 1, 263, 1, 1, 1, 1511, 1571, 1, 1, 347, 359, 1811, 383, 1931, 1, 1, 2111 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The only composite in this sequence is a(2) = 217 = 7*31. All other a(n) are equal to 1 (for n=3,7,12,15,17,18,19,20,21,22,26,28,31,33,34,35,38,39,45,46..) or prime: a(1) = 5, all other primes in a(n) belong to A068231[n]: Primes congruent to 11 (mod 12). It appears that every prime from A068231[n] except 11 shows up in a(n) just once.

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..500

FORMULA

a(n) = Denominator[BernoulliB[10Prime[n]]]/66.

MATHEMATICA

Table[Denominator[BernoulliB[10Prime[n]]]/66, {n, 1, 47}]

CROSSREFS

Cf. A068231, A119456, A051230, A051229, A002445.

Sequence in context: A269823 A206457 A291806 * A235456 A159808 A159317

Adjacent sequences:  A119654 A119655 A119656 * A119658 A119659 A119660

KEYWORD

nonn

AUTHOR

Alexander Adamchuk, Jul 28 2006

STATUS

approved

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Last modified November 29 05:05 EST 2021. Contains 349416 sequences. (Running on oeis4.)