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 A155899 #6 Apr 20 2013 04:48:49 %S A155899 0,0,1,1,0,1,0,0,0,1,1,0,0,1,0,0,0,1,0,0,1,0,0,0,0,0,0,1,0,0,0,0,0,1, %T A155899 1,0,0,0,0,1,0,0,0,0,1,0,0,1,0,0,0,1,0,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0, %U A155899 0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0 %N A155899 Square matrix T(m,n)=1 if (2m+1)^(2n-1)-2 is prime, 0 otherwise; read by antidiagonals. %C A155899 In some sense the "minimal" possible generalization of the pattern of Mersenne primes (cf. A000043) is to consider powers of odd numbers minus 2. Here only odd powers are considered. %o A155899 (PARI) T = matrix( 19,19,m,n, isprime((2*m+1)^(2*n-1)-2)) ; %o A155899 A155899 = concat( vector( vecmin( matsize(T)), i, vector( i, j, T[j,i-j+1]))) %Y A155899 Cf. A084714, A128472, A014224, A109080, A090669, A128455, A128457, A128458, A128459, A128460, A128461. %K A155899 easy,nonn,tabl %O A155899 1,1 %A A155899 _M. F. Hasler_, Feb 01 2009