cp's OEIS Frontend

A153011 Sum of proper divisors, minus the number of proper divisors, minus cototient of n, plus 1.

%I A153011 #11 Oct 08 2018 18:10:55
%S A153011 1,0,0,0,0,0,0,1,0,0,0,4,0,0,0,4,0,5,0,6,0,0,0,14,0,0,2,8,0,14,0,11,0,
%T A153011 0,0,24,0,0,0,20,0,18,0,12,8,0,0,36,0,9,0,14,0,24,0,26,0,0,0,54,0,0,
%U A153011 10,26,0,26,0,18,0,22,0,65,0,0,10,20,0,30,0,50,10,0,0,70,0,0,0,38,0,68,0,24,0
%N A153011 Sum of proper divisors, minus the number of proper divisors, minus cototient of n, plus 1.
%H A153011 Antti Karttunen, <a href="/A153011/b153011.txt">Table of n, a(n) for n = 1..11880</a>
%H A153011 Antti Karttunen, <a href="/A153011/a153011.txt">Data supplement: n, a(n) computed for n = 1..100000</a>
%F A153011 a(n) = A152770(n) - A051953(n) + 1.
%p A153011 A000203 := proc(n) numtheory[sigma](n) ; end: A000005 := proc(n) numtheory[tau](n) ; end: A152770 := proc(n) A000203(n)-A000005(n)-n+ 1; end: A051953 := proc(n) n - numtheory[phi](n) ; end: A153011 := proc(n) A152770(n)-A051953(n)+1 ; end: seq(A153011(n),n=1..120) ; # _R. J. Mathar_, Feb 19 2009
%o A153011 (PARI) A153011(n) = (2+eulerphi(n)+sigma(n)-numdiv(n)-(2*n)); \\ _Antti Karttunen_, Oct 08 2018
%Y A153011 Cf. A000005, A000010, A000203, A001065, A032741, A051953, A152770.
%K A153011 easy,nonn
%O A153011 1,12
%A A153011 _Omar E. Pol_, Dec 23 2008
%E A153011 More terms from _R. J. Mathar_, Feb 19 2009