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A177697
Sums of 3 distinct primorials.
2
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.
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
KEYWORD
easy,nonn
AUTHOR
Jonathan Vos Post, May 11 2010
STATUS
approved