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A066783 Integers of the form (prime(k)+1)/phi(k), by order of appearance. 0
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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified November 28 20:58 EST 2021. Contains 349415 sequences. (Running on oeis4.)