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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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified September 22 22:24 EDT 2020. Contains 337291 sequences. (Running on oeis4.)