Minimum number k such that the k-th tetrahedral number is not smaller than n!.

Terms

a(0) =1a(1) =2a(2) =3a(3) =5a(4) =8a(5) =16a(6) =31a(7) =62a(8) =129a(9) =279a(10) =621a(11) =1421a(12) =3343a(13) =8057a(14) =19870a(15) =50071a(16) =128747a(17) =337414a(18) =900358a(19) =2443947a(20) =6742667a(21) =18893218a(22) =53729800a(23) =154983562a(24) =453174686a(25) =1342528227a(26) =4027584682a(27) =12230119228a(28) =37574801086a(29) =116753643340