A097531 Least k such that k*P(n)#-P(n+7) and k*P(n)#+P(n+7) are both primes with P(i)=i-th prime and P(i)#=i-th primorial.

11, 5, 2, 1, 1, 1, 4, 10, 4, 2, 26, 28, 1, 22, 87, 20, 7, 27, 42, 19, 6, 19, 187, 110, 51, 129, 128, 23, 440, 83, 49, 404, 72, 3, 80, 359, 418, 136, 169, 428, 195, 360, 355, 443, 609, 33, 406, 223, 891, 250, 488, 1853, 1356, 224, 31, 923, 254, 60, 234, 1667, 8, 231, 733

Offset

1,1

Links

Table of n, a(n) for n=1..63.

Mathematica

Primorial[n_] := Product[ Prime[i], {i, n}]; f[n_] := Block[{k = 1, p = Primorial[n], q = Prime[n + 7]}, While[k*p - q < 2 || !PrimeQ[k*p - q] || !PrimeQ[k*p + q], k++ ]; k]; Table[ f[n], {n, 63}] (* Robert G. Wilson v, Aug 31 2004 *)

Crossrefs

Sequence in context: A298892 A038318 A010186 * A131029 A033331 A229192

Adjacent sequences: A097528 A097529 A097530 * A097532 A097533 A097534

Keyword

easy,nonn

Author

Pierre CAMI, Aug 27 2004

Extensions

More terms from Robert G. Wilson v, Aug 31 2004

Status

approved