A177697 Sums of 3 distinct primorials.

9, 33, 37, 38, 213, 217, 218, 241, 242, 246, 2313, 2317, 2318, 2341, 2342, 2346, 2521, 2522, 2526, 2550, 30033, 30037, 30038, 30061, 30062, 30066, 30241, 30242, 30246, 30270, 32341, 32342, 32346, 32370, 32550, 510513, 510517, 510518, 510541, 510542

Offset

1,1

Comments

This is to numbers that are the sum of 3 different primes (A124867) as primorials (A002110) are to primes (A000040). The subsequence of primes among these sums of 3 distinct primorials begins: 37, 241, 2341, 2521, 30241, 32341, 512821, 540541.

Links

Table of n, a(n) for n=1..40.

Formula

{a(n)} = {A002110(i) + A002110(j) + A002110(k) for i =/= j, i =/= k, j =/= k}.

Example

9 = 6+2+1
33 = 30+2+1
37 = 30+6+1
38 = 30+6+2
213 = 210+2+1

Mathematica

Take[Total/@Subsets[Join[{1}, FoldList[Times, Prime[Range[10]]]], {3}]// Union, 40] (* Harvey P. Dale, Nov 07 2017 *)

Crossrefs

Cf. A000040, A002110, A006862, A038609, A124867, A177689.

Sequence in context: A231764 A208136 A130444 * A287534 A145849 A111045

Adjacent sequences: A177694 A177695 A177696 * A177698 A177699 A177700

Keyword

easy,nonn

Author

Jonathan Vos Post, May 11 2010

Status

approved