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 A378309 #11 Nov 24 2024 09:38:10 %S A378309 0,2,2,2,2,2,2,3,2,2,2,3,2,2,2,4,2,3,2,3,2,2,2,4,2,2,3,3,2,3,2,5,2,2, %T A378309 2,4,2,2,2,4,2,3,2,3,3,2,2,5,2,3,2,3,2,4,2,4,2,2,2,4,2,2,3,6,2,3,2,3, %U A378309 2,3,2,5,2,2,3,3,2,3,2,5,4,2,2,4,2,2,2,4,2,4 %N A378309 a(n) = A010051(n) + A001222(n). %H A378309 Paolo Xausa, <a href="/A378309/b378309.txt">Table of n, a(n) for n = 1..10000</a> %F A378309 a(n) = A113903(n) - A113903(n-1). %F A378309 a(n) = 2 for prime n. %F A378309 a(2*k) = A073093(k), for k >= 2. %t A378309 Array[Boole[PrimeQ[#]] + PrimeOmega[#] &, 100] %o A378309 (PARI) a(n) = isprime(n) + bigomega(n); \\ _Michel Marcus_, Nov 23 2024 %Y A378309 Cf. A001222, A010051, A073093. %Y A378309 First differences of A113903. %K A378309 nonn,easy %O A378309 1,2 %A A378309 _Paolo Xausa_, Nov 22 2024