OFFSET
1,2
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000 (terms 1..1000 from Donovan Johnson)
MATHEMATICA
a048995[n_Integer] := Module[{t = Table[i, {i, n}], a048050, k},
a048050[m_] := Plus @@ Take[Divisors[m], {2, -2}];
Do[
If[a048050[k] == 0 || a048050[k] > n, Null, t[[a048050[k]]] = 0],
{k, 2, n^2}];
Drop[DeleteDuplicates[t], {2}]
]; a048995[660] (* Michael De Vlieger, Nov 30 2014 *)
PROG
(PARI) mx=8479; v=vector(mx); for(i=2, mx^2, ch=sigma(i)-i-1; if(ch<=mx, if(ch>0, v[ch]=1))); c=0; for(i=1, mx, if(v[i]==0, c++; write("b048995.txt", c " " i))) /* Donovan Johnson, Feb 11 2013 */
CROSSREFS
KEYWORD
nonn,nice
AUTHOR
Bill Taylor (W.Taylor(AT)math.canterbury.ac.nz)
EXTENSIONS
Corrected and extended by Jud McCranie
STATUS
approved