A262055 Euler pseudoprimes to base 8: composite integers such that abs(8^((n - 1)/2)) == 1 mod n.

9, 21, 65, 105, 133, 273, 341, 481, 511, 561, 585, 1001, 1105, 1281, 1417, 1541, 1661, 1729, 1905, 2047, 2465, 2501, 3201, 3277, 3641, 4033, 4097, 4641, 4681, 4921, 5461, 6305, 6533, 6601, 7161, 8321, 8481, 9265, 9709, 10261, 10585, 10745, 11041, 12545

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000 (terms 1..182 from Daniel Lignon)

Mathematica

eulerPseudoQ[n_?PrimeQ, b_] = False; eulerPseudoQ[n_, b_] := Block[{p = PowerMod[b, (n - 1)/2, n]}, p == Mod[1, n] || p == Mod[-1, n]]; Select[2 Range[11000] + 1, eulerPseudoQ[#, 8] &] (* Michael De Vlieger, Sep 09 2015, after Jean-François Alcover at A006970 *)

Prog

(PARI) for(n=1, 1e5, if( Mod(8, (2*n+1))^n == 1 ||  Mod(8, (2*n+1))^n == 2*n && bigomega(2*n+1) != 1 , print1(2*n+1", "))); \\ Altug Alkan, Oct 11 2015

Crossrefs

Cf. A006970 (base 2), A262051 (base 3), A262052 (base 5), A262053 (base 6), A262054 (base 7), this sequence (base 8).

Sequence in context: A020288 A338007 A147466 * A193276 A173084 A137340

Adjacent sequences: A262052 A262053 A262054 * A262056 A262057 A262058

Keyword

nonn

Author

Daniel Lignon, Sep 09 2015

Status

approved