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 A167746 #16 Aug 02 2017 12:02:33 %S A167746 1,0,0,1,0,1,0,1,1,1,0,1,0,1,1,2,0,1,0,1,1,1,0,2,1,1,1,1,0,1,0,1,1,1, %T A167746 1,2,0,1,1,2,0,1,0,1,1,1,0,1,1,1,1,1,0,2,1,2,1,1,0,2,0,1,1,2,1,1,0,1, %U A167746 1,1,0,1,0,1,1,1,1,1,0,1,2,1,0,2,1,1,1,2,0,2,1,1,1,1,1,2,0,1,1,2,0,1,0,2,1 %N A167746 Number of prime divisors of A001222 (counted with multiplicity), with a(1) = 1 by convention. %C A167746 First 31 terms the same as A050370. %H A167746 Antti Karttunen, <a href="/A167746/b167746.txt">Table of n, a(n) for n = 1..10000</a> %H A167746 <a href="/index/Eu#epf">Index entries for sequences computed from exponents in factorization of n</a> %F A167746 a(1) = 1; for n > 1, a(n) = A001222(A001222(n)). - _Antti Karttunen_, Jul 28 2017 %t A167746 Array[If[# == 1, 1, Nest[PrimeOmega, #, 2]] &, 105] (* _Michael De Vlieger_, Jul 29 2017 *) %o A167746 (Scheme) (define (A167746 n) (if (= 1 n) 1 (A001222 (A001222 n)))) ;; _Antti Karttunen_, Jul 28 2017 %o A167746 (PARI) a(n) = if (n==1, 1, bigomega(bigomega(n))); \\ _Michel Marcus_, Jul 28 2017 %Y A167746 Cf. A001222. %K A167746 nonn %O A167746 1,16 %A A167746 _Vladimir Joseph Stephan Orlovsky_, Nov 10 2009 %E A167746 Name clarified by _Antti Karttunen_, Jul 28 2017