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 A072746 #11 Jul 02 2021 11:28:16 %S A072746 0,0,1,1,2,2,2,2,2,2,2,2,3,3,3,3,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,5,5, %T A072746 5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,6,6,6,6,6,6,6,6, %U A072746 6,6,6,6,6,6,6,6,6,6,6,6,6,6,7,7,7,7,7,7,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8 %N A072746 Number of pairs of primes (p, q) such that, for some integer k, (p+q)/2 = 2^k, 2^(k-1) < p < q, and p <= n. %Y A072746 Cf. A072742, A072743, A071538. %K A072746 nonn %O A072746 1,5 %A A072746 _Reinhard Zumkeller_, Jul 08 2002 %E A072746 Name corrected by _Jon E. Schoenfield_, Jun 30 2021