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 A379055 #10 Dec 18 2024 16:40:22 %S A379055 4,2,4,2,4,2,3,2,3,3,2,3,2,4,2,3,2,3,2,2,4,2,2,3,3,3,2,3,2,3,2,3,2,2, %T A379055 2,3,3,3,3,3,3,2,2,2,2,2,2,3,3,2,2,4,2,2,2,2,4,2,2,3,2,3,2,3,2,3,2,2, %U A379055 4,2,2,2,2,4,2,4,2,2,2,2,2,3,2,2,2,2,3,2,4,2 %N A379055 a(n) = composite(2*n+3) - composite(2*n+1). %H A379055 Paolo Xausa, <a href="/A379055/b379055.txt">Table of n, a(n) for n = 0..10000</a> %t A379055 Differences[Select[Range[300], CompositeQ][[;; ;; 2]]] (* _Paolo Xausa_, Dec 18 2024 *) %Y A379055 First differences of A099861. %Y A379055 Cf. A002808, A099861, A379054. %K A379055 nonn %O A379055 0,1 %A A379055 _N. J. A. Sloane_, Dec 18 2024