A131952 a(n) is the maximal overpseudoprime q to base 2 such that the multiplicative order of 2 mod q equals A143584(n).

2047, 8388607, 1082401, 3277, 536870911, 8727391, 4033, 137438953471, 9588151, 2199023255551, 8796093022207, 838861, 14709241, 140737488355327, 65281, 1016801, 2454285751, 13421773, 9007199254740991, 567767102431, 39268347319, 178956971, 576460752303423487, 80581

Offset: 1

Author

Vladimir Shevelev, Aug 26 2008

Keywords

• nonn

Comments

Or composite terms of A064078.

Examples

			For q=256999, 486737, 2304167 and 536870911, the multiplicative order of 2 mod q is A143584(5) = 29, so a(5) = 536870911.
		

Links

• Jeppe Stig Nielsen, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A143584, A064078, A141232, A122929, A141629, A002326.

Programs

PARI

for(k=1,200,m=polcyclo(k,2);m/=gcd(m,k);m!=1&&!isprime(m)&&print1(m,", ")) \\ Jeppe Stig Nielsen, Aug 31 2020

Extensions

More terms from Hugo Pfoertner, Aug 31 2020