login
A131952
a(n) is the maximal overpseudoprime q to base 2 such that the multiplicative order of 2 mod q equals A143584(n).
2
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
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
KEYWORD
nonn
AUTHOR
Vladimir Shevelev, Aug 26 2008
EXTENSIONS
More terms from Hugo Pfoertner, Aug 31 2020
STATUS
approved