login
A072826
Primes p such that p-1 is a highly composite number.
6
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
KEYWORD
nonn
AUTHOR
Shyam Sunder Gupta, Jul 21 2002
STATUS
approved