A305333 - OEIS

A305333

Let p be the n-th base-5 Wieferich prime (A123692). a(n) is the value of p-1 divided by the multiplicative order of 5 (mod p^2).

1, 2, 1, 4, 1, 1, 16 (list; graph; refs; listen; history; text; internal format)

	OFFSET	`1,2`
	LINKS	`Table of n, a(n) for n=1..7.`
	FORMULA	`a(n) = (A123692(n)-1)/A305332(n).`
	PROG	`(PARI) v=[2, 20771, 40487, 53471161, 1645333507, 6692367337, 188748146801]; for(k=1, #v, my(ord=znorder(Mod(5, v[k]^2))); print1((v[k]-1)/ord, ", "))`
	CROSSREFS	`Cf. A123692, A211241, A305331, A305332.` `Sequence in context: A068009 A140168 A059119 * A127772 A086256 A227964` `Adjacent sequences: A305330 A305331 A305332 * A305334 A305335 A305336`
	KEYWORD	`nonn,hard,more`
	AUTHOR	`Felix Fröhlich, May 30 2018`
	STATUS	`approved`

Last modified July 1 22:23 EDT 2022. Contains 354984 sequences. (Running on oeis4.)