A220569 Smallest prime divisor of prime(n) + prime(n+1) + prime(n+2).

2, 3, 23, 31, 41, 7, 59, 71, 83, 97, 109, 11, 131, 11, 3, 173, 11, 199, 211, 223, 5, 251, 269, 7, 7, 311, 11, 7, 349, 7, 5, 11, 5, 439, 457, 3, 487, 503, 3, 13, 19, 5, 7, 19, 607, 3, 661, 7, 13, 701, 23, 17, 7, 3, 3, 11, 19, 829, 29, 857, 883, 911, 7, 941

Offset

1,1

Links

Zak Seidov, Table of n, a(n) for n = 1..1000

Example

a(6) = 7 because prime(6) + prime(6+1) + prime(6+2) = 13 + 17 + 19 = 49 and the smallest prime factor of 49 is 7.

Prog

(PARI) {a=2; b=3; c=5; for(n=1, 100, s=a+b+c;
dv=divisors(s); print1(dv[2]", "); a=b; b=c; c=nextprime(c+2))}

Crossrefs

Cf. A034961, A034962, A073681.

Sequence in context: A068887 A364142 A260128 * A328940 A024764 A213971

Adjacent sequences: A220566 A220567 A220568 * A220570 A220571 A220572

Keyword

nonn

Author

Zak Seidov, Dec 16 2012

Status

approved