cp's OEIS Frontend

A317048 Numbers k such that both k and k + 2 are consecutive deficient numbers.

%I A317048 #10 Aug 20 2018 04:25:27
%S A317048 5,11,17,19,23,27,29,35,39,41,47,53,55,59,65,69,71,77,79,83,87,89,95,
%T A317048 99,101,103,107,111,113,119,125,131,137,139,143,149,155,159,161,167,
%U A317048 173,175,179,185,191,195,197,199,203,207,209,215,219,221,223,227,233
%N A317048 Numbers k such that both k and k + 2 are consecutive deficient numbers.
%H A317048 Muniru A Asiru, <a href="/A317048/b317048.txt">Table of n, a(n) for n = 1..10000</a>
%p A317048 with(numtheory):  A:=select(k->sigma(k)<2*k,[$1..300]):
%p A317048 a:=seq(A[i],i in select(k->A[k+1]-A[k]=2,[$1..nops(A)-1]));
%o A317048 (GAP) A:=Filtered([1..300],k->Sigma(k)<2*k);;
%o A317048 a:=List(Filtered([1..Length(A)-1],i->A[i+1]-A[i]=2),j->A[j]);
%Y A317048 Subsequence of A005100.
%Y A317048 Numbers j such that both k and k + j are consecutive deficient numbers: A317047 (j=1), this sequence (j=2), A317049 (j=3).
%K A317048 nonn
%O A317048 1,1
%A A317048 _Muniru A Asiru_, Aug 04 2018