A238137 Starting with a(1) = 3, a(2) = 5, a(n+1) is the smallest prime number greater than the previous term a(n) such that there exists k satisfying 1<=k<n, a(n+1) = 2*a(n) - a(k).

3, 5, 7, 11, 17, 23, 29, 41, 53, 83, 113, 173, 233, 293, 353, 593, 953, 1553, 2153, 2753, 5153, 8753, 14753, 20753, 36353, 71153, 105953, 211313, 419873, 733793, 1047713, 2086673, 4102193, 8133233, 14179793, 26272913, 52439873, 90699953, 128960033, 167220113

Offset

1,1

Comments

This sequence is finite. - Alois P. Heinz, Feb 19 2014

Links

Alois P. Heinz, Table of n, a(n) for n = 1..312

Example

a(1) = 3, a(2) = 5, a(3) = 2*5 - 3 = 7, a(4) = 2*7 - 3 = 11, a(5) = 2*11 - 5 = 17, ...

Maple

a:= proc(n) a(n):= `if`(n<3, [3, 5][n], min(select(p->p>a(n-1)
        and isprime(p), {seq(2*a(n-1)-a(k), k=1..n-2)})[]))
    end:
seq(a(n), n=1..45);  # Alois P. Heinz, Feb 19 2014

Crossrefs

Cf. A000040.

Sequence in context: A108539 A170886 A361823 * A090919 A065557 A266164

Adjacent sequences: A238134 A238135 A238136 * A238138 A238139 A238140

Keyword

nonn,fini,full

Author

Philippe Deléham, Feb 18 2014

Extensions

More terms from Alois P. Heinz, Feb 19 2014

Status

approved