Let S(n)=sigma(|n|)-3*n; sequence gives numbers n such that S(S(S(S(n))))=n. May be called {3,1}-Sociable number of orders 1 or 2 or 4.

A114528

Let S(n)=sigma(|n|)-3*n; sequence gives numbers n such that S(S(S(S(n))))=n. May be called {3,1}-Sociable number of orders 1 or 2 or 4.

Terms

    a(0) =1248a(1) =1596a(2) =28272a(3) =30240a(4) =32760a(5) =463296a(6) =678032a(7) =1906128a(8) =2178540a(9) =4694328a(10) =4697616a(11) =4698072a(12) =11110976a(13) =12865770a(14) =23569920a(15) =30998250a(16) =31235904a(17) =37501072a(18) =45532800a(19) =63723600a(20) =76980288a(21) =95801088a(22) =142990848a(23) =146078592a(24) =163032720a(25) =614533696a(26) =1044244800a(27) =1379454720

External references