A128003 Numbers n such that (37^n - 1)/36 is prime.

13, 71, 181, 251, 463, 521, 7321, 36473, 48157, 87421, 168527, 249341

Offset

1,1

Comments

7321 is a term found by Richard Fischer in 2004. - Alexander Adamchuk, Feb 11 2007

No other terms less than 100000. - Robert Price, Mar 18 2012

Links

Table of n, a(n) for n=1..12.

H. Dubner, Generalized repunit primes, Math. Comp., 61 (1993), 927-930.

H. Lifchitz, Mersenne and Fermat primes field

Index to primes in various ranges, form ((k+1)^n-1)/k

Mathematica

Select[Prime[Range[100]], PrimeQ[(37^#-1)/36]&]

Prog

(PARI) is(n)=ispseudoprime((37^n-1)/36) \\ Charles R Greathouse IV, Feb 17 2017

Crossrefs

Sequence in context: A340842 A253776 A158941 * A060103 A332943 A141989

Adjacent sequences: A128000 A128001 A128002 * A128004 A128005 A128006

Keyword

hard,more,nonn

Author

Alexander Adamchuk, Feb 11 2007

Extensions

a(7) from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 05 2008

a(8)-a(10) from Robert Price, Mar 18 2012

a(11) from Paul Bourdelais, Aug 05 2019

a(12) from Paul Bourdelais, Aug 04 2020

Status

approved