A192285 Primitive pseudo anti-perfect numbers

5, 7, 8, 17, 22, 23, 31, 33, 38, 39, 41, 52, 53, 59, 67, 71, 73, 74, 81, 83, 94, 101, 103, 108, 109, 116, 122, 127, 129, 137, 143, 149, 151, 157, 158, 167, 171, 172, 178, 179, 193, 199, 214, 237, 241, 247, 257, 262, 263, 269, 283, 293, 311, 313, 319, 331, 333

Offset

1,1

Comments

A primitive pseudo anti-perfect number is a pseudo anti-perfect number that is not a multiple of any other pseudo anti-perfect number.

Like A006036 but using anti-divisors.

Subset of A192270.

Links

Table of n, a(n) for n=1..57.

Maple

with(combinat);
P:=proc(i)
local a, j, k, n, ok, S, v;
v:=array(1..10000); j:=0;
for n from 1 to i do
  a:={};
  for k from 2 to n-1 do
    if abs((n mod k)- k/2) < 1 then a:=a union {k}; fi;
  od;
  S:=subsets(a);
  while not S[finished] do
    if convert(S[nextvalue](), `+`)=n then
       if j=0 then j:=1; v[1]:=n; print(n); break;
       else
          ok:=1;
          for k from 1 to j do
              if trunc(n/v[k])=n/v[k] then ok:=0; break; fi;
          od;
          j:=j+1; v[j]:=n; if ok=1 then print(n); fi;
       fi;
    fi;
  od;
od;
end:

Crossrefs

Cf. A006036, A066272, A192270

Sequence in context: A140237 A032683 A182005 * A192123 A353601 A104423

Adjacent sequences: A192282 A192283 A192284 * A192286 A192287 A192288

Keyword

nonn

Author

Paolo P. Lava, Jul 20 2011

Status

approved