A092916 a(n) = A092914(n)/n = the least integer value of (n-1)!/(n*k!).

10, 0, 105, 2240, 1512, 0, 660, 0, 617760, 16016, 225225, 0, 495040, 0, 69768, 18604800, 639967910400, 0, 8855, 284680230912, 1245476010240000, 41993952000, 159845400, 0, 475020, 0, 9939793500, 156068011008000

Offset

6,1

Comments

From Robert Israel, Jun 26 2020: (Start)

If n is prime, (n-1)!/n is not an integer and a(n) is taken to be 0.

If n = 2*p where p is an odd prime, a(n) = (2*p-1)!/(2*p!). (End)

Links

Robert Israel, Table of n, a(n) for n = 6..733

Example

a(9) = 20160/9 = 2240.

Maple

f:= proc(n) local t, v, k;
   if isprime(n) then return 0 fi;
   t:= (n-1)!/n;
   for k from 1 do
     v:= t/k;
     if not v::integer then return t fi;
     t:= v;
   od
end proc:
map(f, [$6..40]); # Robert Israel, Jun 26 2020

Mathematica

a[n_] := Module[{P, r}, For[r = 1, True, r++, P = (n-r)* Pochhammer[n-r+1, r]/n; If[Divisible[P, n], Return[P/n]]]];
Table[a[n], {n, 6, 40}] (* Jean-François Alcover, Feb 07 2023 *)

Prog

(PARI) m=34; for(n=6, m, r=1; p=n-r; while(r<=n&&p%n>0, r++; p=p*(n-r)); print1(p/n, ", "))

Crossrefs

Cf. A092914, A092915.

Sequence in context: A285772 A171008 A167320 * A285780 A285536 A285477

Adjacent sequences: A092913 A092914 A092915 * A092917 A092918 A092919

Keyword

nonn,look

Author

Amarnath Murthy, Mar 16 2004

Extensions

More terms from Klaus Brockhaus, Mar 17 2004

Status

approved