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.

A181335 Partial products of A036691.

Original entry on oeis.org

1, 4, 96, 18432, 31850496, 550376570880, 114126085737676800, 331312591939905257472000, 14427205603578338379772723200000, 10051861189298894268003697526046720000000
Offset: 0

Views

Author

Jonathan Vos Post, Jan 28 2011

Keywords

Comments

Product of the first n compositorial numbers (which are themselves the product of the first n composite numbers). This is to compositorial numbers (A036691), as superfactorials (A000178) are to factorials (A000142).

Examples

			a(3) = 1 * 4 * 24 * 192 = (1) * (1*4) * (1*4*6) * (1*4*6*8), since the first 4 composite numbers are (4, 6, 8) and the 0th compositorial is 1.
		

Crossrefs

Programs

  • Mathematica
    nn=20;cnos=Complement[Range[nn],Prime[Range[PrimePi[nn]]]];Rest[ FoldList[ Times,1,Rest[FoldList[Times,1,cnos]]]] (* Harvey P. Dale, Jun 28 2011 *)

Formula

a(n) = Product_{i=0..n} A036691(i) = Product_{i=0..n} Product_{j=1..i} A002808(j).