cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A081644 Integers congruent to 0, 1, 4, 9 or 16 (mod 25) which are not squares.

Original entry on oeis.org

26, 29, 34, 41, 50, 51, 54, 59, 66, 75, 76, 79, 84, 91, 101, 104, 109, 116, 125, 126, 129, 134, 141, 150, 151, 154, 159, 166, 175, 176, 179, 184, 191, 200, 201, 204, 209, 216, 226, 229, 234, 241, 250, 251, 254, 259, 266, 275, 276, 279, 284, 291, 300, 301, 304
Offset: 1

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Author

Robert G. Wilson v, Mar 26 2003

Keywords

References

  • Mark A. Herkommer, Number Theory, A Programmer's Guide, McGraw-Hill, New York, 1999, page 315.

Programs

  • Maple
    remove(issqr, [seq(seq(25*i+j,j=[0,1,4,9,16]),i=1..50)]); # Robert Israel, Apr 08 2020
  • Mathematica
    Select[ Range[308], (Mod[ #, 25] == 0 || Mod[ #, 25] == 1 || Mod[ #, 25] == 4 || Mod[ #, 25] == 9 || Mod[ #, 25] == 16) && !IntegerQ[ Sqrt[ # ]] & ]