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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A248552 Numbers n such that the smallest prime divisor of n^2+1 is 97. 1
 366, 410, 604, 754, 1336, 1530, 1574, 2156, 2500, 2544, 2694, 3126, 3276, 3470, 3514, 3664, 4096, 4290, 4440, 5066, 5454, 5604, 6186, 6230, 6380, 6424, 6574, 7156, 8126, 8170, 8320, 9140, 9334, 9484, 9916, 10066, 10110, 10260, 10454, 11036, 11230, 11424, 11856 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Or numbers n such that the smallest prime divisor of n^2+1 is A002313(12). a(n)== 22 or 172 (mod 194). LINKS Amiram Eldar, Table of n, a(n) for n = 1..10000 EXAMPLE 366 is in the sequence because 366^2+1= 97*1381. MATHEMATICA lst={}; Do[If[FactorInteger[n^2+1][[1, 1]]==97, AppendTo[lst, n]], {n, 2, 10000}]; lst Select[Range[12000], FactorInteger[#^2+1][[1, 1]]==97&] (* Harvey P. Dale, Aug 11 2017 *) p = 97; ps = Select[Range[p - 1], Mod[#, 4] != 3 && PrimeQ[#] &]; Select[Range[12000], Divisible[(nn = #^2 + 1), p] && ! Or @@ Divisible[nn, ps] &] (* Amiram Eldar, Aug 16 2019 *) CROSSREFS Cf. A089120, A002313, A209874, A248527-A248531, A248549-A248553. Sequence in context: A208398 A258485 A073305 * A259077 A219960 A033174 Adjacent sequences:  A248549 A248550 A248551 * A248553 A248554 A248555 KEYWORD nonn,easy AUTHOR Michel Lagneau, Oct 08 2014 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 27 19:17 EDT 2022. Contains 354897 sequences. (Running on oeis4.)