login
A097497
Floor( prime(n)*(prime(n)+prime(n+1))/prime(n+1)).
0
3, 4, 8, 11, 20, 22, 32, 34, 41, 56, 56, 70, 80, 82, 88, 100, 116, 116, 130, 140, 140, 154, 160, 170, 190, 200, 202, 212, 214, 213, 250, 256, 272, 268, 296, 296, 308, 322, 328, 340, 356, 352, 380, 382, 392, 386, 410, 442, 452, 454, 460, 476, 472, 496, 508, 520
OFFSET
1,1
COMMENTS
if seq(n+1) - seq(n) = 0 or 2 then prime(n) and prime(n+1) are often twins.
FORMULA
Prime(n) is to prime(n+1) as x is to prime(n)+prime(n+1)
EXAMPLE
Starting with the second prime: 3 is to 5 as x is to 8. x = 8*3/5 => 4
PROG
(PARI) p(n) = for(x=1, n, y=prime(x+1)*prime(x+2)/prime(x)+.0; print1(floor(y)", "))
CROSSREFS
Sequence in context: A212550 A024786 A299069 * A332681 A279328 A006167
KEYWORD
frac,nonn
AUTHOR
Cino Hilliard, Aug 24 2004
STATUS
approved