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A195328 Number of bases to which members of A141768 are strong pseudoprimes. 4
2, 4, 6, 18, 50, 54, 162, 242, 450, 486, 882, 1058, 1782, 3042, 3078, 4050, 5202, 9522, 19602, 22050, 36450, 46818, 54450, 66978, 71442, 95922, 124002, 149058, 183618, 190962, 238050, 240570, 263538, 277830, 328050, 466578, 684450, 816642, 977202 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Charles R Greathouse IV, Table of n, a(n) for n = 1..5476

Index entries for sequences related to pseudoprimes

PROG

(PARI) star(n)={n--; n>>valuation(n, 2)};

bases(n)=my(f=factor(n)[, 1], nu=valuation(f[1]-1, 2), nn = star(n)); for(i=2, #f, nu = min(nu, valuation(f[i] - 1, 2)); ); (1 + (2^(#f * nu) - 1) / (2^#f - 1)) * prod(i=1, #f, gcd(nn, star(f[i]))); \\ Given a value of A141768, this function transforms it to a member of this sequence.

CROSSREFS

Cf. A141768, A195327.

Sequence in context: A066894 A233919 A111115 * A294447 A143085 A304756

Adjacent sequences:  A195325 A195326 A195327 * A195329 A195330 A195331

KEYWORD

nonn

AUTHOR

Charles R Greathouse IV, Sep 15 2011

STATUS

approved

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Last modified July 4 12:18 EDT 2020. Contains 335448 sequences. (Running on oeis4.)