A074107 a(n) = Product of (prime + 1) for first n primes - primorial (n).

1, 6, 42, 366, 4602, 66738, 1231314, 25136790, 612982650, 18612572370, 602072009070, 23079296834790, 976751205195990, 43281303292150770, 2090585319354906990, 113506497027753468870, 6842978980142398176930

Offset

1,2

Links

Harvey P. Dale, Table of n, a(n) for n = 1..349

Example

a(3) = (2+1)*(3+1)*(5+1) - 2*3*5 = 72 - 30 = 42.

Maple

for n from 1 to 25 do a[n] := product(ithprime(i)+1, i=1..n)-product(ithprime(i), i=1..n): od:seq(a[j], j=1..25);

Mathematica

Module[{nn=20, p, pr, pr1}, p=Prime[Range[nn]]; pr=FoldList[Times, 1, p]; pr1= FoldList[Times, 1, p+1]; #[[2]]-#[[1]]&/@Rest[Thread[{pr, pr1}]]](* Harvey P. Dale, Feb 07 2015 *)

Crossrefs

Sequence in context: A218817 A368321 A052589 * A187121 A225497 A336950

Adjacent sequences: A074104 A074105 A074106 * A074108 A074109 A074110

Keyword

nonn

Author

Amarnath Murthy, Aug 22 2002

Extensions

More terms from Sascha Kurz, Feb 01 2003

Status

approved