A119740 Primes p such that p+1, p+2, p+3, p+4, p+5 and p+6 have equal number of divisors.

298693, 346501, 1841141, 2192933, 2861461, 3106981, 3375781, 3435589, 3437813, 3865429, 4597013, 6191461, 7016213, 7074901, 7637941, 7918373, 9196309, 10216901, 12798901, 13747429, 14100661, 14171653, 14770981, 14779189

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Example

298693 is a term since 298694, 298695, 298696, 298697, 298698 and 298699 all have 8 divisors:
{1,2,11,22,13577,27154,149347,298694}, {1,3,5,15,19913,59739,99565,298695},
{1,2,4,8,37337,74674,149348,298696}, {1,7,71,497,601,4207,42671,298697},
{1,2,3,6,49783,99566,149349,298698}, {1,19,79,199,1501,3781,15721,298699}.

Mathematica

Select[Prime@Range[1000000], DivisorSigma[0, #+1]==DivisorSigma[0, #+2]==DivisorSigma[0, #+3]==DivisorSigma[0, #+4]==DivisorSigma[0, #+5]==DivisorSigma[0, #+6]&]

Crossrefs

Cf. A008329, A049234, A119705, A119711, A119728, A119730.

Sequence in context: A204334 A048906 A251334 * A254193 A254186 A253798

Adjacent sequences: A119737 A119738 A119739 * A119741 A119742 A119743

Keyword

nonn

Author

Zak Seidov, Jul 29 2006

Status

approved