cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A243758 a(n) = Product_{i=1..n} A234959(i).

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 6, 6, 6, 6, 6, 6, 36, 36, 36, 36, 36, 36, 216, 216, 216, 216, 216, 216, 1296, 1296, 1296, 1296, 1296, 1296, 7776, 7776, 7776, 7776, 7776, 7776, 279936, 279936, 279936, 279936, 279936, 279936, 1679616, 1679616, 1679616, 1679616, 1679616, 1679616, 10077696
Offset: 0

Views

Author

Tom Edgar, Jun 10 2014

Keywords

Comments

This is the generalized factorial for A234959.
a(0) = 1 as it represents the empty product.

Crossrefs

Programs

  • Haskell
    a243758 n = a243758_list !! n
    a243758_list = scanl (*) 1 a234959_list
    -- Reinhard Zumkeller, Feb 09 2015
    
  • Mathematica
    Table[Product[6^IntegerExponent[k, 6], {k, 1, n}], {n, 0, 20}] (* G. C. Greubel, Dec 24 2016 *)
  • PARI
    valp(n,p)=my(s); while(n\=p, s+=n); s
    a(n)=6^valp(n,6) \\ Charles R Greathouse IV, Oct 03 2016
  • Sage
    S=[0]+[6^valuation(i,6) for i in [1..100]]
    [prod(S[1:i+1]) for i in [0..99]]
    

Formula

a(n) = Product_{i=1..n} A234959(i).
a(n) = 6^(A054895(n)).