login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A301590 Primes p such that there are no other solution to A023900(x) = A023900(p) than a power of p. 2
2, 3, 5, 7, 11, 17, 19, 23, 29, 31, 43, 47, 53, 59, 67, 71, 79, 83, 101, 103, 107, 127, 131, 137, 139, 149, 151, 163, 167, 173, 179, 191, 197, 199, 211, 223, 227, 229, 239, 251, 257, 263, 269, 271, 283, 293, 307, 311, 317, 331, 347, 359, 367, 373, 379, 383, 389 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..57.

EXAMPLE

2 is a term because there are no other solution to A023900(x) = A023900(2) than other powers of 2.

PROG

(PARI) f(n) = sumdivmult(n, d, d*moebius(d));

isok(p, vp) = {for (k=p+1, p^2-1, if (f(k) == vp, return (0)); ); return (1); }

lista(nn) = {forprime(p=2, nn, vp = f(p); if (isok(p, vp), print1(p, ", ")); ); }

CROSSREFS

Cf. A023900, A301374.

Complement of A301591.

Sequence in context: A042988 A167135 A129990 * A293194 A162566 A040085

Adjacent sequences:  A301587 A301588 A301589 * A301591 A301592 A301593

KEYWORD

nonn

AUTHOR

Michel Marcus, Mar 24 2018

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
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified June 1 00:27 EDT 2020. Contains 334756 sequences. (Running on oeis4.)