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

1,1

Comments

Or composite terms of A064078.

Links

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

Example

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

Prog

(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

Crossrefs

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

Sequence in context: A069386 A069412 A069438 * A065341 A135976 A236373

Adjacent sequences: A131949 A131950 A131951 * A131953 A131954 A131955

Keyword

nonn

Author

Vladimir Shevelev, Aug 26 2008

Extensions

More terms from Hugo Pfoertner, Aug 31 2020

Status

approved