A335969 Sphenic numbers that are also the sum of three consecutive primes.
1015, 1533, 1645, 2233, 2737, 2915, 3219, 3515, 3745, 3815, 4301, 4503, 4565, 4623, 4697, 4921, 5289, 5621, 6055, 6095, 6213, 6251, 6409, 7055, 7347, 7657, 7847, 8099, 8455, 8569, 8687, 8729, 9499, 9581, 9955, 10105, 10153, 10295, 10735, 11155, 11297, 11315, 11803, 12665, 12805, 12845
Offset: 1
Keywords
Examples
1015 = A007304(140) = A034961(67), 1533 = A007304(226) = A034961(96).
Links
- Robert Israel, Table of n, a(n) for n = 1..10000
Programs
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Maple
P:= select(isprime, [seq(i,i=3..10^4,2)]): P3:= P[1..-3] + P[2..-2] + P[3..-1]: filter:= proc(t) local F; F:= ifactors(t)[2]; nops(F) = 3 and F[1,2]=1 and F[2,2] = 1 and F[3,2]=1 end proc: select(filter, P3); # Robert Israel, Nov 24 2022
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Mathematica
Intersection[ Select[Range[105, 40000,2], 3 == PrimeOmega[#] == PrimeNu[#] &], Total /@ Partition[Prime[Range[40000]], 3, 1]]
Comments