A078155 A078152(n!).

0, 0, 0, 0, 4, 22, 80, 304, 1043, 3538, 12094, 42979, 156237, 587926, 2283038, 9142910, 37708601, 160014979, 697523776, 3119511496, 14295524835, 67052144163, 321571055089, 1575370699764, 7876854373196, 40164235356266, 208699490940770

Offset

1,5

Links

Michael De Vlieger, Table of n, a(n) for n = 1..807

Formula

a(n) = A078152(n!) = A055086(n!) - A000005(n!).

Mathematica

Table[ Length[ Union[ Table[ Floor[w!/j], {j, 1, w!}]]] - DivisorSigma[0, w! ], {w, 1, 11}]
(* Second program: *)
Array[Floor@ Sqrt[4 # + 1] - 1 - DivisorSigma[0, #] &[#!] &, 27] (* Michael De Vlieger, Dec 13 2018 *)

Crossrefs

Cf. A078152, A078153, A078154, A078156, A078157, A078158.

Sequence in context: A347722 A201127 A259709 * A237530 A096167 A060453

Adjacent sequences: A078152 A078153 A078154 * A078156 A078157 A078158

Keyword

nonn

Author

Labos Elemer, Nov 27 2002

Extensions

Extended by Robert G. Wilson v, Dec 02 2002

a(11) corrected and terms a(12) onward added by Max Alekseyev, Feb 12 2012

Status

approved