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 A373149 #10 Dec 17 2024 08:44:46
%S A373149 0,1,2,2,3,3,5,3,4,4,7,4,11,6,5,4,13,5,17,5,7,8,19,5,6,12,6,7,23,6,29,
%T A373149 5,9,14,8,6,31,18,13,6,37,8,41,9,7,20,43,6,10,7,15,13,47,7,10,8,19,24,
%U A373149 53,7,59,30,9,6,14,10,61,15,21,9,67,7,71,32,8,19,12,14,73,7,8,38,79,9,16,42,25,10,83,8,16
%N A373149 Fully additive with a(2) = 1 and a(p) = prevprime(p) for odd primes p.
%H A373149 Antti Karttunen, <a href="/A373149/b373149.txt">Table of n, a(n) for n = 1..16384</a>
%H A373149 <a href="/index/Pri#prime_indices">Index entries for sequences related to prime indices in the factorization of n</a>
%F A373149 Additive with a(p^e) = e*A064989(p).
%t A373149 A373149[n_] := If[n == 1, 0, Total[MapApply[#2*If[# == 2, 1, NextPrime[#, -1]] &, FactorInteger[n]]]];
%t A373149 Array[A373149, 100] (* _Paolo Xausa_, Dec 17 2024 *)
%o A373149 (PARI) A373149(n) = { my(f = factor(n)); sum(i = 1, #f~, f[i, 2]*if(2==f[i, 1], 1, precprime(f[i, 1] - 1))); };
%Y A373149 Cf. A064989, A151799.
%Y A373149 Cf. also A001414, A059975, A276085.
%K A373149 nonn
%O A373149 1,3
%A A373149 _Antti Karttunen_, Jun 02 2024