cp's OEIS Frontend

A125238 Differences between consecutive deficient numbers.

%I A125238 #22 Oct 21 2020 09:09:45
%S A125238 1,1,1,1,2,1,1,1,1,2,1,1,1,1,2,2,1,1,2,1,1,2,2,1,1,1,1,2,1,1,2,2,1,1,
%T A125238 1,1,2,1,1,1,1,2,2,1,1,2,1,1,1,1,2,1,1,2,2,1,1,1,1,2,2,1,1,2,1,1,2,2,
%U A125238 1,1,1,1,2,1,1,2,2,2,1,1,2,1,1,2,2,1,1
%N A125238 Differences between consecutive deficient numbers.
%C A125238 The first 3 occurs at n=4340. - _R. J. Mathar_, Jul 08 2015
%H A125238 R. J. Mathar, <a href="/A125238/b125238.txt">Table of n, a(n) for n = 1..1000</a>
%F A125238 a(n) = A005100(n+1) - A005100(n).
%F A125238 Asymptotic mean: lim_{n->oo} (1/n) Sum_{k=1..n} a(k) = 1/A318172 = 1.3291... - _Amiram Eldar_, Oct 21 2020
%e A125238 a(1) = 1 because 2-1 = 1.
%e A125238 a(5) = 2 because 7-5 = 2.
%p A125238 A125238 := proc(n)
%p A125238     A005100(n+1)-A005100(n) ;
%p A125238 end proc: # _R. J. Mathar_, Jul 08 2015
%t A125238 Differences@ Select[Range@ 105, DivisorSigma[1, #] < 2 # &] (* _Michael De Vlieger_, Jun 29 2018 *)
%o A125238 (GAP) A:=Filtered([1..100],n->Sigma(n)<2*n);; a:=List([1..Length(A)-1],i->A[i+1]-A[i]); # _Muniru A Asiru_, Jun 26 2018
%Y A125238 Cf. A005100, A094268, A125115, A318172.
%K A125238 easy,nonn
%O A125238 1,5
%A A125238 _Jason G. Wurtzel_, Nov 25 2006