A119660 - OEIS

A119660

Prime factor of the distinct numbers appearing as denominators of Bernoulli numbers A090801 that is greater than all previous a(n). a(1) = 2.

2, 3, 5, 7, 11, 23, 47, 59, 83, 107, 167, 179, 227, 239, 263, 347, 359, 383, 443, 467, 479, 503, 563, 587, 647, 659, 719, 827, 839, 863, 887, 983, 1019, 1187, 1223, 1259, 1283, 1307, 1319, 1367, 1439, 1487, 1499, 1523, 1619, 1787

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OFFSET

1,1

COMMENTS

a(n) is identical to A079148[n] up to a(14)=227. Most a(n) except 2,3,239,443,647,659,827,1223,1259,1499,1787... belong to A005385[n]: Safe primes p: (p-1)/2 is also prime.

Except for 2 and 3, the same as A092307. - T. D. Noe, Sep 25 2006

LINKS

Table of n, a(n) for n=1..46.

EXAMPLE

A090801[n] begins {1, 2, 6, 30, 42, 66, 138, 282, 330, 354, 498, 510, 642, 690, ...} = {1, {2,1}, {2,3}, {2,3,5}, {2,3,7}, {2,3,11}, {2,3,23}, {2,3,47}, {2,3,5,11}, {2,3,59}, {2,3,83}, {2,3,5,17}, {2,3,107}, {2,3,5,23}, ...}.

a(1) = 2, a(2) = 3, a(3) = 5, a(4) = 7, a(5) = 11, a(6) = 23, a(7) = 47, a(8) = 59, a(9) = 83, a(10) = 107.

CROSSREFS

Cf. A090801, A079148, A005385.

Sequence in context: A036344 A165802 A107798 * A079148 A107367 A373044

Adjacent sequences: A119657 A119658 A119659 * A119661 A119662 A119663

KEYWORD

nonn

AUTHOR

Alexander Adamchuk, Jul 28 2006

STATUS

approved