A107058 a(n) = smallest number m>0 such that prime(n)*prime(n+1)-m is a prime.
1, 2, 4, 4, 4, 10, 6, 4, 6, 12, 18, 6, 4, 4, 14, 6, 6, 8, 6, 4, 18, 4, 18, 4, 6, 4, 18, 6, 16, 4, 4, 8, 6, 4, 16, 18, 2, 10, 12, 18, 18, 22, 6, 10, 4, 6, 2, 22, 6, 4, 6, 6, 34, 8, 2, 18, 6, 26, 24, 30, 6, 12, 6, 16, 30, 10, 8, 6, 22, 6, 8, 4, 2, 8, 18, 26, 10, 4, 12, 30, 10, 12, 4, 24, 6, 6, 6
Offset: 1
Keywords
Links
- Seiichi Manyama, Table of n, a(n) for n = 1..10000
Crossrefs
Programs
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PARI
a(n) = { my(m=0, v = prime(n)*prime(n+1)); while (! isprime(v-m), m++;); return (m);} \\ Michel Marcus, Apr 19 2013
Comments