cp's OEIS Frontend

A061244 Prime numbers with odd digits in ascending order.

%I A061244 #12 Oct 26 2019 17:49:55
%S A061244 3,5,7,11,13,17,19,37,59,79,113,137,139,157,179,199,337,359,379,557,
%T A061244 577,599,1117,1399,1559,1579,1777,1999,3359,3557,3559,3779,5557,5779,
%U A061244 11113,11117,11119,11159,11177,11399,11579,11777,11779,13337,13339
%N A061244 Prime numbers with odd digits in ascending order.
%H A061244 Robert Israel, <a href="/A061244/b061244.txt">Table of n, a(n) for n = 1..10000</a>
%e A061244 37 is a term since 3 and 7 are odd digits and 3 < 7.
%p A061244 A061244:= {}:
%p A061244 for d from 1 to 20 do
%p A061244   for n1 from 0 to d do
%p A061244     x1:= (10^n1-1)/9;
%p A061244     for n3 from 0 to d-n1 do
%p A061244       x3:= x1*10^n3 + (10^n3-1)/9*3;
%p A061244       for n5 from 0 to d-n1-n3 do
%p A061244         x5:= x3*10^n5 + (10^n5-1)/9*5;
%p A061244         for n7 from 0 to d-n1-n3-n5 do
%p A061244           x7:= x5*10^n7 + (10^n7-1)/9*7;
%p A061244           n9:= d-n1-n3-n5-n7;
%p A061244           x:= x7*10^n9 + (10^n9-1);
%p A061244           if isprime(x) then
%p A061244             A061244:= A061244 union {x};
%p A061244           fi
%p A061244 od od od od od:
%p A061244 A061244;
%p A061244 # _Robert Israel_, Apr 20 2014
%Y A061244 Cf. A061245, A028864, A052015.
%K A061244 nonn,base
%O A061244 1,1
%A A061244 _Amarnath Murthy_, Apr 23 2001
%E A061244 More terms from _Patrick De Geest_, Jun 04 2001