a(n) = the number of "isolated divisors" of n!. A positive divisor, k, of n is isolated if neither (k-1) nor (k+1) divides n.

A133952

a(n) = the number of "isolated divisors" of n!. A positive divisor, k, of n is isolated if neither (k-1) nor (k+1) divides n.

Terms

    a(0) =1a(1) =0a(2) =1a(3) =4a(4) =10a(5) =19a(6) =43a(7) =77a(8) =137a(9) =243a(10) =497a(11) =749a(12) =1520a(13) =2518a(14) =3952a(15) =5294a(16) =10628a(17) =14564a(18) =29199a(19) =40855a(20) =60605a(21) =95786a(22) =191700a(23) =242580a(24) =339732a(25) =531896a(26) =677048a(27) =916946a(28) =1834106a(29) =2332346

External references