Numbers k such that S(S(S(k))) = k, with S(n) = sigma(n)/4: 1/4-sociable numbers of order 1 or 3.
A355279
Numbers k such that S(S(S(k))) = k, with S(n) = sigma(n)/4: 1/4-sociable numbers of order 1 or 3.
Terms
- a(0) =30240a(1) =32760a(2) =2178540a(3) =23569920a(4) =45532800a(5) =46475520a(6) =48933360a(7) =50995620a(8) =60933600a(9) =69995520a(10) =72807696a(11) =142990848
External references
- oeis: A355279