This site is supported by donations to The OEIS Foundation.

 Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing. Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A007672 a(n) = A002034(n)!/n. (Formerly M1669) 5
 1, 1, 2, 6, 24, 1, 720, 3, 80, 12, 3628800, 2, 479001600, 360, 8, 45, 20922789888000, 40, 6402373705728000, 6, 240, 1814400, 1124000727777607680000, 1, 145152, 239500800, 13440, 180, 304888344611713860501504000000 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 REFERENCES N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). LINKS A. J. Kempner, Miscellanea, Amer. Math. Monthly, 25 (1918), 201-210 [ See Section II, "Concerning the smallest integer m! divisible by a given integer n". ] MATHEMATICA a[n_] := Module[{m = 1, x = n, as = 1, p}, While[x > 1, m++; p = GCD[x, m]; x = x/p; as *= m/p]; as]; Array[a, 30] (* Jean-François Alcover, May 09 2017, after Antonio Roldán *) PROG (PARI) a(n)={local(m=1, x=n, as=1, p); while(x>1, m++; p=gcd(x, m); x=x/p; as*=m/p); as} \\ Antonio Roldán, Apr 04 2015 CROSSREFS Sequence in context: A327426 A086554 A213324 * A322255 A084337 A323615 Adjacent sequences:  A007669 A007670 A007671 * A007673 A007674 A007675 KEYWORD nonn,nice AUTHOR STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 13 06:26 EST 2019. Contains 329968 sequences. (Running on oeis4.)