A228810 Numbers k, excluding primes and squares of primes, such that gcd(k, numerator of H(k-1)) > 1, where the harmonic number H(j) = Sum_{i=1..j} 1/i.

88, 1290, 9339, 102619, 102729, 116424, 116512, 343594, 372889, 904428, 1129909, 1129942, 1130019, 1280554, 1280664, 2351307, 12723966, 12728166, 12809227, 12818637, 12869013

Offset

1,1

Comments

The corresponding GCDs are given by A228811.

Links

Table of n, a(n) for n=1..21.

Wikipedia, Greatest common divisor

Prog

(PARI) isA000430(n)=isprime(n) || (issquare(n, &n) && isprime(n))
H=0; for(n=2, 1e6, H+=1/(n-1); if(!isA000430(n) && gcd(n, numerator(H))>1, print1(n", "))) \\ Charles R Greathouse IV, Sep 04 2013

Crossrefs

Cf. A001008, A228811.

Sequence in context: A249294 A239274 A235018 * A245954 A248047 A107422

Adjacent sequences: A228807 A228808 A228809 * A228811 A228812 A228813

Keyword

nonn

Author

Arkadiusz Wesolowski, Sep 04 2013

Extensions

a(14)-a(15) from Charles R Greathouse IV, Sep 04 2013

a(16)-a(21) from Charles R Greathouse IV, Sep 09 2013

Status

approved