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 A241910 #9 May 15 2014 10:20:00 %S A241910 0,0,0,0,1,0,0,1,0,0,1,2,0,1,0,1,0,0,1,2,0,0,1,0,1,0,1,2,3,0,0,1,2,0, %T A241910 0,1,2,0,1,0,1,0,0,1,2,3,0,1,0,1,0,1,2,0,1,2,0,0,1,2,0,0,1,2,3,4,0,1, %U A241910 0,1,0,1,0,1,2,3,0,0,1,0,1,0,1,2,3,0,0,1,2,0,0,1,2,0,1,2,0,1,0,0,1,2,3,4,0,1,0,1,2,0,1,0,1,2,0,0,1,2,3,0 %N A241910 After a(1)=0, numbers 0 .. bigomega(n)-1, followed by numbers 0 .. bigomega(n+1)-1, etc., where bigomega(n)=A001222(n) is the number of prime factors of n (with repetition). %H A241910 Antti Karttunen, <a href="/A241910/b241910.txt">Table of n, a(n) for n = 1..10000</a> %F A241910 a(1)=0, a(n) = n - A022559(A082288(n)-1) - 2. %e A241910 Viewed as an irregular table, the sequence is constructed as: %e A241910 "Row" %e A241910 [1] 0; (by convention, a(1)=0) %e A241910 [2] 0; (because bigomega(2)=1, we have here terms from 0 to 0) %e A241910 [3] 0; (same with 3, bigomega(3)=1) %e A241910 [4] 0, 1; (as bigomega(4)=2, we have terms from 0 to 2-1) %e A241910 [5] 0; %e A241910 [6] 0, 1; %e A241910 [7] 0; %e A241910 [8] 0, 1, 2; (as bigomega(8)=3, we have terms from 0 to 3-1). %e A241910 etc. %o A241910 (Scheme, with _Antti Karttunen_'s IntSeq-library) %o A241910 (define (A241910 n) (if (= n 1) 0 (- n (+ 2 (A022559 (- (A082288 n) 1)))))) %Y A241910 One less than A241911. %Y A241910 Cf. A022559, A082288, A112798, A241914. %K A241910 nonn,tabf %O A241910 1,12 %A A241910 _Antti Karttunen_, May 01 2014