A263483 a(n) = prime(n)+(prime(n) modulo 6).

4, 6, 10, 8, 16, 14, 22, 20, 28, 34, 32, 38, 46, 44, 52, 58, 64, 62, 68, 76, 74, 80, 88, 94, 98, 106, 104, 112, 110, 118, 128, 136, 142, 140, 154, 152, 158, 164, 172, 178, 184, 182, 196, 194, 202, 200, 212, 224, 232, 230, 238, 244, 242, 256, 262, 268, 274, 272, 278, 286, 284, 298, 308, 316, 314

Offset

1,1

Comments

For n>2, a(n)-a(n+1)=2 iff prime(n) and prime(n+1) are twin primes; e.g., a(3)-a(4)=10-8=2 and prime(3)=5 and prime(4)=7 are twin primes.

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Formula

a(n) = A000040(n) + A039704(n). - Michel Marcus, Oct 27 2015

Maple

p:= 1:
for n from 1 to 100 do
  p:= nextprime(p);
  A[n]:= p + (p mod 6);
od:
seq(A[n], n=1..100); # Robert Israel, Jul 18 2018

Mathematica

Table[(p=Prime[n])+Mod[p, 6], {n, 100}]

Prog

(PARI) a(n) = apply(x->(x + x%6), prime(n)); \\ Michel Marcus, Oct 27 2015

Crossrefs

Cf. A000040, A039704.

Sequence in context: A028279 A114743 A089546 * A363700 A249982 A292767

Adjacent sequences: A263480 A263481 A263482 * A263484 A263485 A263486

Keyword

nonn

Author

Zak Seidov, Oct 19 2015

Status

approved