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A079449 Primes p such that there is at least one integer x satisfying p=x*tau(x)+1 where tau(x)=A000005(x), the number of divisors of x. 1
2, 5, 7, 11, 13, 23, 41, 47, 59, 61, 73, 83, 89, 107, 109, 137, 157, 167, 179, 193, 227, 229, 233, 241, 263, 271, 277, 313, 337, 347, 349, 359, 373, 379, 383, 409, 433, 449, 457, 461, 467, 479, 503, 563, 569, 587, 709, 719, 733, 809, 821, 839, 853, 857, 863 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..55.

EXAMPLE

12*tau(12)=72 hence 73 is in the sequence.

PROG

(PARI) lista(nn) = {forprime(p=2, nn, for (n=1, p, if (n*numdiv(n)+1 == p, print1(p, ", "); break; ); ); ); } \\ Michel Marcus, Dec 01 2013

CROSSREFS

Cf. A079448.

Sequence in context: A098170 A120330 A023216 * A236071 A038885 A079379

Adjacent sequences:  A079446 A079447 A079448 * A079450 A079451 A079452

KEYWORD

nonn

AUTHOR

Benoit Cloitre, Jan 13 2003

STATUS

approved

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Last modified December 17 18:04 EST 2014. Contains 252034 sequences.