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 A178503 #7 Jan 01 2024 20:02:45 %S A178503 1,1,1,2,2,3,3,5,5,6,6,8,7,9,10,12,10,13,11,15,15,16,14,19,19,19,21, %T A178503 22,19,24,20,27,26,26,28,30,25,29,31,34,28,35,29,37,38,36,32,42,41,43, %U A178503 42,44,37,47,47,49,47,47,42,53,43,50,55,58,56,58,48,59,58,62,51,65,52,61 %N A178503 n minus totally additive with a(p)=PrimePi(p), where PrimePi(n)=A000720(n). %F A178503 a(n) = A000027(n) - A056239(n). %p A178503 From _R. J. Mathar_, Apr 20 2010: (Start) %p A178503 A056239 := proc(n) add( numtheory[pi](op(1,p))*op(2,p), p = ifactors(n)[2]) ; end proc: %p A178503 A178503 := proc(n) n-A056239(n) ; end proc: seq(A178503(n),n=1..80) ; (End) %Y A178503 Cf. A000027, A000720, A056239. %K A178503 nonn %O A178503 1,4 %A A178503 _Juri-Stepan Gerasimov_, Apr 19 2010 %E A178503 Corrected (a 27 replaced with 28) by _R. J. Mathar_, Apr 20 2010