A161360 Decimal expansion of Product_p p#/(p#-1).

2, 4, 9, 5, 8, 0, 6, 5, 1, 4, 0, 5, 9, 8, 3, 8, 2, 7, 2, 7, 7, 4, 9, 7, 9, 2, 0, 4, 9, 3, 0, 1, 5, 3, 4, 3, 7, 2, 6, 1, 0, 3, 7, 9, 3, 7, 6, 1, 5, 5, 0, 7, 7, 9, 6, 3, 9, 6, 9, 1, 6, 5, 3, 8, 9, 5, 1, 3, 5, 7, 2, 2, 2, 6, 4, 9, 6, 5, 6, 5, 6, 9, 0, 4, 5, 5, 5, 7, 0, 3, 4, 8, 5, 6, 1, 3, 5, 4, 0, 0, 1, 6, 2, 5, 2

Offset: 1

Author

Franklin T. Adams-Watters, Jun 07 2009

Keywords

• cons
• nonn

Comments

By p# we mean the primorial number which is the product of the primes less than or equal to p.

Examples

			2/1 * 6/5 * 30/29 * ... = 2.495806514059838272774979204930153...
		

Crossrefs

Cf. A002110, A034386, A025487, A064648.

Programs

Mathematica

RealDigits[Times@@(#/(#-1)&/@Rest[FoldList[Times,1,Prime[Range[100]]]]), 10,120][[1]] (* Harvey P. Dale, Mar 15 2015 *)

PARI

h(n)=local(p,pl,r);p=2;pl=1;r=1.;while(p
				

Formula

This number is equal to Sum_k 1/A025487(k).