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.
%I A177031 #11 Mar 31 2012 13:22:06 %S A177031 0,1,5,7,9,12,15,17,92,130,131,154,175,189,190,236,271,290,365,372, %T A177031 518,558,574,635,646,748,804,829,1066,1197,1236,1559,1941,2112,2324 %N A177031 Exponents n for which P#*2^n-1 is a lower twin prime, where P is the prime associated with n in A176994. %e A177031 2*3*2^0-1=5, 2*3*2^0+1=7 twin prime of 5 so a(1)=0 %e A177031 2*3*2^1-1=11, 2*3*2^1+1=13 twin prime of 11 so a(2)=1 %e A177031 2*3*2^2-1=23 prime but not twin prime %e A177031 2*3*2^3-1=47 prime but not twin prime %e A177031 2*3*2^4-1=95 composite %e A177031 2*3*5*2^4-1=479 prime but not twin prime %e A177031 2*3*2^5-1=191, 2*3*2^5+1=193 twin prime of 191 so a(3)=5 %Y A177031 Cf. A001359, A034386, A176994. %K A177031 nonn %O A177031 1,3 %A A177031 _Pierre CAMI_, Dec 09 2010