login
This site is supported by donations to The OEIS Foundation.

 

Logo

Annual Appeal: Please make a donation (tax deductible in USA) to keep the OEIS running. Over 5000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
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: A256396 A120330 A023216 * A236071 A038885 A079379

Adjacent sequences:  A079446 A079447 A079448 * A079450 A079451 A079452

KEYWORD

nonn

AUTHOR

Benoit Cloitre, Jan 13 2003

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified December 5 19:19 EST 2016. Contains 278770 sequences.