This site is supported by donations to The OEIS Foundation.

 Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing. Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A242959 Numbers n such that 5^A000010(n) == 1 (mod n^2). 11
 2, 20771, 40487, 41542, 80974, 83084, 161948, 643901, 1255097, 1287802, 1391657, 1931703, 2510194, 2575604, 2783314, 3765291, 3863406, 4174971, 5020388, 5151208, 5566628, 7530582, 7726812, 8349942, 10040776, 11133256, 15061164, 15308227, 15453624, 16699884 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Felix Fröhlich, Table of n, a(n) for n = 1..75 PROG (PARI) for(n=2, 10^9, if(Mod(5, n^2)^(eulerphi(n))==1, print1(n, ", "))) CROSSREFS Cf. A077816, A242958, A242960. If a(n) is prime, then a(n) is in A123692. Sequence in context: A124364 A173156 A214598 * A123692 A290741 A261362 Adjacent sequences:  A242956 A242957 A242958 * A242960 A242961 A242962 KEYWORD nonn AUTHOR Felix Fröhlich, May 27 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 | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 8 12:07 EST 2019. Contains 329862 sequences. (Running on oeis4.)