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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A259020 Numbers n such that n^2 + 1 is a divisorial prime (A258455). 2
 1, 6, 10, 14, 26, 74, 94, 134, 146, 206, 314, 326, 386, 466, 576, 634, 674, 1094, 1174, 1294, 1306, 1354, 1366, 1546, 1654, 1766, 1774, 1894, 1966, 2026, 2126, 2174, 2326, 2594, 2654, 2746, 2916, 2974, 2986, 3046, 3106, 3134, 3136, 3214, 3254, 3274, 3314, 3326 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS The divisorial primes are primes of the form p = 1 + Product_{d|k} d = 1 + A007955(k) for some k. Supersequence of A259021. Subsequence of A005574. First deviation from A259021 is at a(15). LINKS Table of n, a(n) for n=1..48. OEIS wiki, Divisorial primes EXAMPLE The number 6 is in sequence because prime 37 = 6^2 + 1 is prime of the form p = 1 + Product_{d|k} d = 1 + A007955(k) for k = 6. PROG (Magma) Set(Sort([1] cat [Floor(Sqrt(&*(Divisors(n)))): n in [3..10000] | IsPrime(&*(Divisors(n))+1)])) CROSSREFS Cf. A005574, A007955, A048943, A118369, A258455, A258897, A259021, A259023. Sequence in context: A315239 A119623 A129119 * A259021 A171251 A074980 Adjacent sequences: A259017 A259018 A259019 * A259021 A259022 A259023 KEYWORD nonn AUTHOR Jaroslav Krizek, Sep 01 2015 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 June 23 10:38 EDT 2024. Contains 373643 sequences. (Running on oeis4.)