A340817 a(n) is the least prime of the form prime(n)*p + prime(n+1)*q + prime(n+2)*r where p,q,r are consecutive primes.

83, 127, 167, 2749, 257, 307, 1427, 431, 769, 1811, 617, 4261, 2843, 2633, 881, 1459, 2087, 5023, 6199, 1831, 3461, 1373, 1459, 8353, 1567, 1607, 1657, 8353, 8867, 4111, 4231, 11801, 20983, 3529, 4903, 34283, 5227, 5399, 7307, 13103, 18311, 2917, 2957, 6311, 15101, 5113, 3407, 3457, 19433, 3581, 23689

Offset

2,1

Links

Robert Israel, Table of n, a(n) for n = 2..10000

Formula

a(n) = prime(n)*A340821(n) + prime(n+1)*A151800(A340821(n)) + prime(n+2)*A151800(A151800(A340821(n))).

Example

a(3) = 5*3 + 7*5 + 11*7 = 167.

Maple

f:= proc(n) local k, t;
  for k from 1 do
     t:=ithprime(n)*ithprime(k) + ithprime(n+1)*ithprime(k+1) + ithprime(n+2)*ithprime(k+2);
     if isprime(t) then return t fi;
  od
end proc:
map(f, [$2..30]);

Crossrefs

Cf. A151800, A340821.

Sequence in context: A288880 A126117 A096279 * A261087 A140771 A142309

Adjacent sequences: A340814 A340815 A340816 * A340818 A340819 A340820

Keyword

nonn

Author

J. M. Bergot and Robert Israel, Jan 22 2021

Status

approved