# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/

Search: id:a286628
Showing 1-1 of 1

%I A286628 #12 Jul 02 2017 03:58:58
%S A286628 1,0,2,0,1,1,3,0,0,0,2,0,1,1,1,0,1,0,2,1,2,1,3,0,0,0,1,0,1,1,5,0,2,0,
%T A286628 2,0,1,1,1,0,1,1,2,1,1,1,4,0,1,0,1,0,1,1,1,1,2,0,2,1,1,2,0,0,1,1,2,1,
%U A286628 2,1,3,0,1,0,0,0,2,1,4,0,0,0,2,0,1,1,1,0,1,0,2,1,3,2,1,1,1,0,1,0,1,1,3,0,2,0,2,0,1,1,1,0,1,1,2,1,0,1,2,0
%N A286628 a(n) = exponent of the highest power of A000005(n) (number of divisors of n) dividing A000203(n) (sum of divisors of n), a(1) = 1.
%C A286628 a(1) = 1 by convention.
%H A286628 Antti Karttunen, <a href="/load/view.php?a=aHR0cDovL29laXMub3JnL0EyODY2MjgvYjI4NjYyOC50eHQ">Table of n, a(n) for n = 1..10000</a>
%F A286628 a(n) = A286561(A000203(n), A000005(n)).
%e A286628 A000005(6) = 4, A000203(6) = 12, 4^1 is the highest power of 4 which divides 12, thus a(6) = 1.
%e A286628 A000005(7) = 2, A000203(7) = 8, 2^3 is the highest power of 2 which divides 8, thus a(7) = 3.
%e A286628 A000005(8) = 4, A000203(8) = 15, 4^0 = 1 is the highest power of 4 which divides 15, thus a(8) = 0.
%o A286628 (PARI) A286628(n) = if(1==n,n,valuation(sigma(n), numdiv(n)));
%Y A286628 Cf. A000005, A000203, A051281, A054025, A286561, A286627.
%Y A286628 Cf. A049642 (positions of zeros), A003601 (of nonzeros).
%K A286628 nonn
%O A286628 1,3
%A A286628 _Antti Karttunen_, Jun 30 2017

# Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE