A247906 - OEIS

A247906

a(n) = n-th pseudoprime to base n.

561, 286, 341, 781, 1105, 1105, 133, 364, 703, 793, 1105, 1099, 1891, 6541, 1271, 3991, 1649, 1849, 3059, 7363, 2047, 1738, 4537, 1128, 3145, 2993, 5365, 4069, 4097, 7421, 2465, 11305, 2937, 16589, 4495, 2044, 6601, 26885, 13073, 6892, 22945, 3885, 8695, 10879

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OFFSET

2,1

LINKS

Table of n, a(n) for n=2..45.

EXAMPLE

a(2) = A001567(2) = 561.

a(3) = A005935(3) = 286.

PROG

(PARI) for(n=2, 20, i=0; forcomposite(c=2, 1e9, if(Mod(n, c)^(c-1)==1, i++; if(i==n, print1(c, ", "); i=0; break({1}))); if(c==1e9, print1(">1e9, "))))

CROSSREFS

Cf. A007535, A098650.

Cf. Pseudoprimes to base b: A001567 (b=2), A005935 (b=3), A020136 (b=4), A005936 (b=5), A005937 (b=6), A005938 (b=7), A020137 (b=8), A020138 (b=9).

Sequence in context: A265261 A234936 A274443 * A278338 A184047 A344673

Adjacent sequences: A247903 A247904 A247905 * A247907 A247908 A247909

KEYWORD

nonn

AUTHOR

Felix Fröhlich, Sep 26 2014

STATUS

approved