A344889 Divide the positive integers into subsets of lengths given by successive primes. a(n) is the product of primes contained in the n-th subset.

2, 15, 7, 2431, 437, 1363783, 107113, 1249792339, 56606581, 1741209542339, 8811899415119, 1107997261359193637, 113411646442333, 5544791201146623008917, 785518504414223, 88816991126218293876923, 140194949408966090156937953, 517859057576547860552412883, 6474009927400912083137

Offset: 1

Author

Paolo Xausa, Jun 01 2021

Keywords

• nonn

Examples

			a(1) = 2 because the first subset is [1,2] (length = 2) and the product of primes contained in it is 2.
a(2) = 15 because the second subset is [3,4,5] (length = 3) and the product of primes contained in it is 3 * 5 = 15.
a(3) = 7 because the third subset is [6,7,8,9,10] (length = 5) and the product of primes contained in it is 7.
a(4) = 2431 because the fourth subset is [11,12,13,14,15,16,17] (length = 7) and the product of primes contained in it is 11 * 13 * 17 = 2431.
		

Crossrefs

Cf. A000040, A002110, A344718.

Programs

Mathematica

nterms=100;list = TakeList[Range[Sum[Prime[i],{i,nterms}]],Prime[Range[nterms]]];listprime=Map[Select[#,PrimeQ]&,list];Map[Apply[Times,#]&,listprime]