cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A178322 Numbers n such that 156/101*(10^(4n)-1)-1 is prime.

This page as a plain text file.
%I A178322 #13 Mar 20 2015 19:16:41
%S A178322 1,2,5,29,30,108,679,4478,8736,17000,22427,22731
%N A178322 Numbers n such that 156/101*(10^(4n)-1)-1 is prime.
%C A178322 If n is in the sequence then m=91*(156/101*(10^(4n)-1)-1) is a term of A072394. Namely if n is a term of this sequence then for m=1/101*(14196*10^(4n)-23387), we have sigma(m)=reversal(m)-m (see comment lines of A072394).
%C A178322 Numbers corresponding to the larger terms are probable primes.
%C A178322 Next term exceeds 3500. - _Robert G. Wilson v_, Aug 08 2011.
%C A178322 a(13) > 40000. - _Robert Price_, May 23 2014
%t A178322 Select[Range[700], PrimeQ[156/101*(10^(4 #) - 1) - 1] &]
%Y A178322 Cf. A072394, A178321.
%K A178322 more,nonn
%O A178322 1,2
%A A178322 _Farideh Firoozbakht_, May 26 2010
%E A178322 a(8)-a(12) from _Robert Price_, May 23 2014