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A317048 Numbers k such that both k and k + 2 are consecutive deficient numbers. 4

%I #10 Aug 20 2018 04:25:27

%S 5,11,17,19,23,27,29,35,39,41,47,53,55,59,65,69,71,77,79,83,87,89,95,

%T 99,101,103,107,111,113,119,125,131,137,139,143,149,155,159,161,167,

%U 173,175,179,185,191,195,197,199,203,207,209,215,219,221,223,227,233

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

%H Muniru A Asiru, <a href="/A317048/b317048.txt">Table of n, a(n) for n = 1..10000</a>

%p with(numtheory): A:=select(k->sigma(k)<2*k,[$1..300]):

%p a:=seq(A[i],i in select(k->A[k+1]-A[k]=2,[$1..nops(A)-1]));

%o (GAP) A:=Filtered([1..300],k->Sigma(k)<2*k);;

%o a:=List(Filtered([1..Length(A)-1],i->A[i+1]-A[i]=2),j->A[j]);

%Y Subsequence of A005100.

%Y Numbers j such that both k and k + j are consecutive deficient numbers: A317047 (j=1), this sequence (j=2), A317049 (j=3).

%K nonn

%O 1,1

%A _Muniru A Asiru_, Aug 04 2018

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Last modified July 12 11:12 EDT 2024. Contains 374244 sequences. (Running on oeis4.)