A072288 Smallest prime factor of googolplex + n that exceeds 13, or 1 if googolplex + n is 13-smooth.

316912650057057350374175801344000001

Offset: 1

Author

Ed Pegg Jr and Robert G. Wilson v, Nov 21 2002

Keywords

• hard
• nonn
• bref
• more
• less

Comments

a(2) is not known. After a(1) the sequence continues ?, 1429, 1129, 29, ?, 53, 427169, 5501, 19, 59, 1327, 1645318771, 61, 211, 17, 1831, ?, 43, 389, 173, 233886337, 139, 1451, 18797, 31, 37, 8297, 19, 13879, ?, 9241, 17, 29, ...

The question marks indicate terms > 10^14. - Dario Alpern, May 17 2003

Links

• Tanya Khovanova, Non Recursions
• Dario Alejandro Alpern, Factors of 1000 numbers starting from googolplex
• Robert Harley, Factors of Googolplex+1 (Found some terms)
• Eric Weisstein's World of Mathematics, Googolplex
• Index entries for one-term sequences

Crossrefs

Cf. A067007, A078814, A341116.

Programs

Mathematica

(* For any individual n *) k = 17; While[ !PrimeQ[k] || PowerMod[10, 10^100, k] + n != k, k += 2]; k

Extensions

Name edited by Peter Munn, Feb 20 2025