A072275 Least m such that one less than m-th prime has n divisors (or 0 if no such prime exists).

2, 3, 4, 7, 6, 0, 11, 12, 30, 0, 18, 0, 44, 79, 47, 0, 42, 0, 53, 106, 1581, 0, 82, 211, 1470, 595, 319, 0, 169, 0, 216, 2819, 177975, 38836904, 279, 0, 62947, 41203, 326, 0, 647, 0, 1795, 907, 8719625, 0, 369, 0, 841, 12545382, 6180, 0, 820, 190066763704011

Offset

2,1

Links

Table of n, a(n) for n=2..55.

Mathematica

Do[ If[ !PrimeQ[n], k = 1; While[ Length[ Divisors[ Prime[k] - 1]] != n, k++ ]; Print[k], Print[0]], {n, 6, 34}]

Crossrefs

A000040(a(n)) = A066814(n).

Sequence in context: A273014 A336321 A359446 * A122989 A222246 A353828

Adjacent sequences: A072272 A072273 A072274 * A072276 A072277 A072278

Keyword

nonn

Author

Lekraj Beedassy, Jul 09 2002

Extensions

More terms from Robert G. Wilson v, Jul 15 2002

a(35) inserted and a(46)-a(55) added by Amiram Eldar, Feb 06 2019

Status

approved