The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A300478 Numbers n where more than one positive integer k with 1 < k < n exists such that n^k + k^n is prime. 1
 114, 318, 590, 790, 903, 1036, 1158, 1263, 1298, 1545, 1588 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Numbers n such that A300477(n) > 1. Subsequence of A162488. LINKS EXAMPLE 114 is a term of the sequence, since 114^k + k^114 is prime for two values of k with 1 < k < 114, namely, k=67 and k=97. PROG (PARI) a300477(n) = my(i=0); for(k=2, n-1, if(ispseudoprime(n^k+k^n), i++)); i is(n) = a300477(n) > 1 CROSSREFS Cf. A162488, A300477. Sequence in context: A171374 A228962 A250725 * A305066 A322541 A323758 Adjacent sequences:  A300475 A300476 A300477 * A300479 A300480 A300481 KEYWORD nonn,hard,more AUTHOR Felix FrÃ¶hlich, Mar 06 2018 EXTENSIONS a(7)-a(11) from Robert Israel, Sep 25 2020 STATUS approved

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

Last modified May 28 16:37 EDT 2022. Contains 354119 sequences. (Running on oeis4.)