OFFSET
0,1
COMMENTS
If A096502(n) <> 0, i.e., there is a prime p of the form 2^k - 2*n - 1, then 0 < a(n) <= 2^(k-1)*p since 2^(k-1)*p has deficiency 2*n. - Robert Israel, Oct 29 2017
LINKS
Michel Marcus, Table of n, a(n) for n = 0..8220 (terms <= 10^10) (terms 0..1644 from Robert Israel)
MAPLE
N:= 100: # to get a(0)..a(N)
count:= 0:
for n from 1 while count < N+1 do
d:= abs(2*n - numtheory:-sigma(n));
if d::even and d <= 2*N and not assigned(A[d/2]) then
count:= count+1; A[d/2]:= n;
fi
od:
seq(A[i], i=0..N); # Robert Israel, Oct 29 2017
PROG
(PARI) a033879(n) = 2*n-sigma(n)
a(n) = my(k=1); while(1, if(abs(a033879(k))==2*n, return(k)); k++) \\ Felix Fröhlich, Oct 29 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Michel Marcus and Omar E. Pol, Oct 29 2017
STATUS
approved