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A114245 Number of Fermat pseudoprimes to base 3 less than 10^n. 7
0, 1, 6, 23, 78, 246, 760, 2155, 5804, 15472, 39871, 102839 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Table of n, a(n) for n=1..12.

Eric Weisstein's World of Mathematics, FermatPseudoprime

Index entries for sequences related to pseudoprimes

FORMULA

A005935(a(n)) < 10^n; A005935(a(n)+1) > 10^n. - R. J. Mathar, Feb 10 2007

PROG

(PARI) isFps(n, b)= { if(isprime(n), return(0) ) ; if( (b^(n-1)) % n == 1, return(1), return(0) ) ; } { a=0 ; e=1 ; for(n=1, 10^12, if( n == 10^e, e++ ; print(a) ; ) ; a += isFps(n, 3) ; ) ; } \\ R. J. Mathar, Feb 10 2007

CROSSREFS

Cf. A005935, A114247, A114249.

Sequence in context: A058751 A034359 A220148 * A220238 A078798 A027043

Adjacent sequences:  A114242 A114243 A114244 * A114246 A114247 A114248

KEYWORD

nonn,more

AUTHOR

Eric W. Weisstein, Nov 18 2005

EXTENSIONS

a(9)-a(10) from Washington Bomfim, Mar 02 2012

a(11)-a(12) from Hiroaki Yamanouchi, Sep 25 2015

STATUS

approved

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Last modified May 19 17:01 EDT 2019. Contains 323395 sequences. (Running on oeis4.)