A072828 Primes p such that p+1 is a highly composite number.

3, 5, 11, 23, 47, 59, 179, 239, 359, 719, 839, 1259, 5039, 7559, 10079, 55439, 110879, 166319, 665279, 1081079, 1441439, 6486479, 32432399, 61261199, 698377679, 735134399, 1102701599, 1396755359, 2205403199, 20951330399, 41902660799

Offset: 1

Author

Shyam Sunder Gupta, Jul 21 2002

Keywords

• nonn

Examples

			47 is a term because it is prime and also 47+1=48 is a highly composite number.
		

Links

• Amiram Eldar, Table of n, a(n) for n = 1..441 (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.

Crossrefs

Cf. A002182, A068507, A072826, A214873, A306588.

Formula

a(n) == 2 (mod 3) for n > 1 (because highly composite numbers > 4 are == 0 (mod 3); see A002182). - Jonathan Sondow, Nov 05 2015

a(n) = A002182(A306588(n)) - 1. - Amiram Eldar, Dec 03 2020