A088682 a(n) = prime(3*n+1) - prime(3*n-1).

4, 6, 10, 10, 10, 8, 8, 14, 6, 18, 8, 8, 10, 12, 6, 16, 10, 16, 8, 6, 18, 18, 12, 14, 10, 12, 12, 8, 14, 6, 12, 10, 20, 16, 8, 12, 12, 14, 6, 8, 10, 18, 14, 12, 12, 24, 12, 6, 18, 18, 6, 12, 12, 20, 12, 18, 8, 8, 12, 24, 6, 14, 28, 18, 12, 16, 8, 22, 6, 8, 6, 8, 12, 28, 6, 14, 8, 12, 6, 24

Offset: 1

Author

Zak Seidov, Oct 05 2003

Keywords

• easy
• nonn

Comments

Previous name was: Partition the primes in triples starting with 3: {3, 5, 7}, {11, 13, 17}, {19, 23, 29}, {31, 37, 41}, {43, 47, 53}, {59, 61, 67}, {71, 73, 79}, {83, 89, 97}, {101, 103, 107}. Sequence gives differences between smallest and largest prime in each triple.

Minimal difference is 6 (for 3-tuplet) except first triple. Repeating 6 means successive 3-tuplets, see A088683, A088684, ...

Crossrefs

Cf. A088680, A078584, A088683, A088684.

Programs

Mathematica

Table[Prime[3n+1]-Prime[3n-1],{n,80}] (* Harvey P. Dale, Jul 28 2020 *)

PARI

a(n) = prime(3*n+1) - prime(3*n-1); \\ Michel Marcus, Oct 05 2013

Extensions

New name from Michel Marcus, Oct 05 2013