A318964 Numbers k such that both k and k+1 are the product of exactly five distinct primes.

378014, 421134, 483405, 486590, 486794, 489345, 507129, 545258, 549185, 558789, 558830, 634809, 637329, 663585, 667029, 690234, 720290, 776985, 782690, 823745, 824109, 853005, 853034, 855645, 873885, 883245, 892905, 935714, 945230, 968253, 987734, 999005, 1005081, 1013726

Offset

1,1

Links

Seiichi Manyama, Table of n, a(n) for n = 1..1000

Example

n | a(n)                           | a(n)+1
--+--------------------------------+--------------------------------
1 | 378014 = 2 * 7 * 13 * 31 *  67 | 378015 = 3 *  5 * 11 * 29 * 79
2 | 421134 = 2 * 3 *  7 * 37 * 271 | 421135 = 5 * 11 * 13 * 19 * 31
3 | 483405 = 3 * 5 * 13 * 37 *  67 | 483406 = 2 *  7 * 11 * 43 * 73

Prog

(PARI) is(n) = omega(n)==5 && omega(n+1)==5 && bigomega(n)==5 && bigomega(n+1)==5 \\ Felix Fröhlich, Sep 06 2018

Crossrefs

Subsequence of A140079.

Cf. A046387, A052215, A215217, A263990, A318896.

Sequence in context: A089444 A203740 A283030 * A226361 A238078 A133975

Adjacent sequences: A318961 A318962 A318963 * A318965 A318966 A318967

Keyword

nonn

Author

Seiichi Manyama, Sep 06 2018

Status

approved