A072826 Primes p such that p-1 is a highly composite number.

2, 3, 5, 7, 13, 37, 61, 181, 241, 2521, 7561, 15121, 20161, 45361, 55441, 110881, 332641, 498961, 4324321, 14414401, 43243201, 110270161, 183783601, 367567201, 4655851201, 13967553601, 73329656401, 293318625601, 1606268664001

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..431 (terms below 10^1000; terms 1..300 from T. D. Noe)

Benny Lim, Prime Numbers Generated From Highly Composite Numbers, Parabola Magazine, volume 54, issue 3, 2018.

Formula

a(n) = A002182(A306587(n)) + 1. - Amiram Eldar, Dec 03 2020

Example

13 is a term because it is a prime such that 13-1=12 is a highly composite number.

Crossrefs

Cf. A002182 (highly composite numbers), A072828 (with p+1 instead), A306587.

Sequence in context: A050779 A052291 A256072 * A084761 A038965 A295738

Adjacent sequences: A072823 A072824 A072825 * A072827 A072828 A072829

Keyword

nonn

Author

Shyam Sunder Gupta, Jul 21 2002

Status

approved