A376892 Numbers k such that the sum of the first k greater of twin primes is a greater of twin prime.
1, 45, 105, 675, 987, 1431, 1593, 1677, 1785, 1875, 2037, 2541, 3039, 3045, 3051, 3183, 3267, 3531, 3699, 4113, 4239, 4377, 4443, 5643, 5673, 5709, 6027, 6543, 6615, 6771, 6891, 6915, 6999, 8043, 8109, 8313, 8607, 8739, 10197, 10569, 11103, 11139, 11361, 11787, 12045
Offset: 1
Keywords
Links
- Robert Israel, Table of n, a(n) for n = 1..10000
- Eric Weisstein's World of Mathematics, Twin Primes.
Programs
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Maple
K:= 1: count:= 1: s:= 5: k:= 1: for p from 7 by 6 do if isprime(p) and isprime(p-2) then k:= k+1; s:= s+p; if s mod 6 = 1 and isprime(s) and isprime(s-2) then count:= count+1; K:= K, k; if count = 100 then break fi; fi fi od: K; # Robert Israel, Nov 08 2024 -
PARI
lista(nn) = my(v=select(p->isprime(p-2), primes(nn)), s = vector(#v)); s[1] = v[1]; for (i=2, #v, s[i] = s[i-1]+v[i]); Vec(select(x->(isprime(x) && isprime(x-2)), s, 1)); \\ Michel Marcus, Oct 10 2024