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.

A145049 Primes p of the form 4k+1 for which s=17 is the least positive integer such that sp-(floor(sqrt(sp)))^2 is a square.

Original entry on oeis.org

3037, 3169, 3257, 3769, 4013, 4421, 4793, 4957, 5237, 5297, 5701, 5821, 5881, 6373, 6689, 6761, 6949, 7013, 7213, 7417, 7481, 7549, 7621, 7757, 8389, 8461, 8537, 8681, 8753, 9049, 9133, 9277, 9349, 9733, 10133, 10529, 10601, 11093, 11177, 11257, 11677, 11701
Offset: 1

Views

Author

Vladimir Shevelev, Sep 30 2008

Keywords

Examples

			a(1)=3037 since p=3037 is the least prime of the form 4k+1 for which sp-(floor(sqrt(sp)))^2 is not a square for s=1..16, but 17p-(floor(sqrt(17p)))^2 is a square (for p=3037 it is 100).
		

Crossrefs

Programs

  • Maple
    filter:= proc(p) local s;
      if not isprime(p) then return false fi;
      for s from 1 to 17 do
        if issqr(s*p - floor(sqrt(s*p))^2) then return evalb(s=17) fi
      od;
      false
    end proc:
    select(filter, [seq(i,i=1..10000,4)]); # Robert Israel, Jan 22 2024