OFFSET
1,2
LINKS
Muniru A Asiru, Table of n, a(n) for n = 1..10000
MAPLE
A:=select(k->sigma(k)<2*k, [$1..200]): a:=seq(A[i], i in select(n->A[n+1]-A[n]=1, [$1..nops(A)-1]));
PROG
(GAP) A:=Filtered([1..200], k->Sigma(k)<2*k);;
a:=List(Filtered([1..Length(A)-1], i->A[i+1]-A[i]=1), j->A[j]);
(PARI) isok(n) = (sigma(n) < 2*n) && (sigma(n+1) < 2*(n+1)); \\ Michel Marcus, Aug 20 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
Muniru A Asiru, Aug 04 2018
STATUS
approved