A066783 Integers of the form (prime(k)+1)/phi(k), by order of appearance.

3, 4, 3, 4, 3, 7, 3, 5, 4, 6, 9, 8, 9, 7, 14, 10, 14, 11, 15, 19, 12, 6, 16, 20, 23, 10, 10, 8, 28, 8, 14, 22, 16, 24, 16, 13, 16, 20, 15, 18, 23, 10, 22, 20, 35, 10, 36, 24, 19, 34, 30, 26, 12, 28, 19, 18, 25, 19, 39, 57, 30, 20, 40, 27, 27, 41, 45, 43, 47, 29

Offset

1,1

Links

Table of n, a(n) for n=1..70.

Example

a(10) = 6 because 15 is the 10th integer such that (prime(15)+1)/phi(15) = 48/8 = 6 is an integer.

Prog

(PARI) lista(nn) = {my(p=1); for(k=1, nn, if((1+p=nextprime(p+1))%eulerphi(k) == 0, print1((p+1)/eulerphi(k), ", "))); } \\ Jinyuan Wang, Apr 06 2020

Crossrefs

Cf. A000010.

Sequence in context: A345439 A095925 A242744 * A046536 A052384 A276867

Adjacent sequences: A066780 A066781 A066782 * A066784 A066785 A066786

Keyword

nonn

Author

Benoit Cloitre, Jan 18 2002

Extensions

More terms from Jinyuan Wang, Apr 06 2020

Status

approved