A080377 Each a(n) is a difference of suitable consecutive primes, a(n)=Prime[1+A080376(n)]-Prime[A080376(n)]. a(n+1) is the smallest prime-difference [from A001223] which has prime-factor not present in previous terms or was present but at lower power.

2, 4, 6, 8, 14, 10, 18, 22, 34, 16, 26, 32, 38, 50, 62, 54, 58, 46, 64, 86, 82, 74, 98, 106, 94, 118, 122, 128, 146, 134, 142, 162, 178, 158

Offset

1,1

Links

Table of n, a(n) for n=1..34.

Example

18 is the 7th term:in first-6th ones {2,4,6,8,14,10} 3 does not occur with power 2 unlike in 18; 22 is the 8th term: in first-7th terms 11 is not a prime factor unlike 22. several even numbers do not arise in this sequence, e.g.:12,20,36,48, etc..

Mathematica

s=1; Do[s1=s; s=LCM[s, d=Prime[n+1]-Prime[n]]; If[Greater[s, s1], Print[d]], {n, 1, 10000000}]

Crossrefs

Cf. A001223, A080374-A080376.

Sequence in context: A072791 A058320 A014320 * A086526 A086529 A054409

Adjacent sequences: A080374 A080375 A080376 * A080378 A080379 A080380

Keyword

nonn

Author

Labos Elemer, Feb 27 2003

Status

approved