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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A028773 Nonsquares mod 60. 1
 2, 3, 5, 6, 7, 8, 10, 11, 12, 13, 14, 15, 17, 18, 19, 20, 22, 23, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 37, 38, 39, 41, 42, 43, 44, 46, 47, 48, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS EXAMPLE x^2 = 20 mod 60 has no solutions, so 20 is in the sequence. x^2 = 21 mod 60 has the following solutions: x = 9, x = 21, x = 39, x = 51. Hence 21 is not in the sequence. MATHEMATICA Complement[Range[59], PowerMod[Range[60], 2, 60]] (* Alonso del Arte, Jan 13 2017 *) PROG (Scala) (0 to 59).diff((1 to 60).map(n => n * n % 60)) // Alonso del Arte, Jan 03 2020 CROSSREFS Cf. A010421. Sequence in context: A039251 A283296 A028797 * A028813 A158276 A028793 Adjacent sequences:  A028770 A028771 A028772 * A028774 A028775 A028776 KEYWORD nonn,fini,full,easy AUTHOR 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 April 10 22:19 EDT 2021. Contains 342856 sequences. (Running on oeis4.)