A226977 Places n where A225867(n) <= 2.

7, 8, 11, 17, 23, 29, 41, 47, 59, 71, 239, 359, 419, 839

Offset

1,1

Comments

Except for a(2)=8, all terms are prime.

Is this sequence finite?

There are no other terms up to 86000. - Peter J. C. Moses, Jun 28 2013

There are no more terms up to 10^9. - Charles R Greathouse IV, Nov 25 2014

Links

Table of n, a(n) for n=1..14.

Prog

(PARI) is(n)=for(k=2, n\2-1, if(sumdiv(n+k, d, (n+d)%k==0 && d>1)>2, return(0))); n>6 \\ Charles R Greathouse IV, Nov 25 2014

Crossrefs

Cf. A225867, A049002.

Sequence in context: A145826 A102963 A117619 * A098731 A348784 A294483

Adjacent sequences: A226974 A226975 A226976 * A226978 A226979 A226980

Keyword

nonn,more

Author

Vladimir Shevelev, Jun 27 2013

Status

approved