A060737 Number of distinct differences between consecutive divisors of n! (ordered by size).
0, 0, 1, 2, 4, 9, 15, 27, 44, 72, 116, 230, 379, 716, 1154, 1858, 2589, 5014, 7299, 15276, 21901, 33146, 52298, 102918, 136647, 200669, 327572, 432396, 596869, 1220172, 1603092, 3074018, 3752018, 5433507, 8555035, 11952469, 14590378, 30158257, 46318453, 66458379
Offset: 0
Keywords
Examples
For n = 4, n! = 24; divisors = {1,2,3,4,6,8,12,24}; differences = {1,1,1,2,2,4,12}, distinct differences = {1,2,4,12}, so a(4) = 4.
Programs
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Mathematica
a[n_ ] := Length[Union[Drop[d=Divisors[n! ], 1]-Drop[d, -1]]] Table[Length[Union[Differences[Divisors[n!]]]],{n,0,40}] (* Harvey P. Dale, Nov 22 2021 *)
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PARI
a(n) = {my(v = List(), d1 = 1); fordiv(n!, d, if(d > 1, listput(v, d-d1); d1 = d)); #Set(v);} \\ Amiram Eldar, Jun 15 2024
Formula
a(n) = A060682(n!).
Extensions
Edited by Dean Hickerson, Jan 22 2002
More terms from Ryan Propper, Mar 22 2006
a(37)-a(39) from Amiram Eldar, Jun 15 2024