A242833 - OEIS

A242833

Primes formed by the initial digits of the decimal expansion of 1/19, starting at the first nonzero digit in the expansion.

%I #16 Oct 22 2014 03:54:38

%S 5,52631,5263157894736842105263157,

%T 52631578947368421052631578947368421052631578947368421052631

%N Primes formed by the initial digits of the decimal expansion of 1/19, starting at the first nonzero digit in the expansion.

%C a(5) has 95 digits and a(6) has 907 digits. - _Michel Marcus_, May 27 2014

%H Jon E. Schoenfield, <a href="/A242833/b242833.txt">Table of n, a(n) for n = 1..6</a>

%o (PARI) lista(nn) = {v = [5,2,6,3,1,5,7,8,9,4,7,3,6,8,4,2,1,0]; n = 0; for (i=0, nn, n = 10*n+ v[(i % 18)+1]; if (ispseudoprime(n), print1(n, ", ")););} \\ _Michel Marcus_, May 27 2014

%Y Cf. A021023.

%Y Corresponding sequences for 1/k: A242824 (k=7), A093676 (k=12), A242826 (k=13), A242827(k=14), A242828 (k=17).

%K base,nonn

%O 1,1

%A _Felix Fröhlich_, May 23 2014