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.

A328803 The minimum value of j + k where j and k are positive integers with j^2 + k^2 = A001481(n).

Original entry on oeis.org

0, 1, 2, 2, 3, 4, 3, 4, 5, 4, 5, 6, 6, 5, 6, 7, 8, 8, 6, 7, 8, 9, 9, 7, 8, 10, 9, 10, 11, 8, 9, 10, 12, 11, 12, 12, 9, 10, 11, 13, 12, 13, 14, 10, 11, 12, 14, 13, 15, 14, 15, 11, 12, 13, 16, 14, 16, 15, 12, 13, 16, 14, 17, 15, 17, 16, 18, 18, 13, 14, 15, 16
Offset: 1

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Author

Peter Kagey, Oct 27 2019

Keywords

Examples

			For n = 14, A001481(14) = 25 = 0^2 + 5^2 = 3^2 + 4^2, so a(14) = min{0+5, 3+4} = 5.
		

Crossrefs

Programs

  • Maple
    N:= 1000: # for terms where A001481(n)<=N
    for s from 0 to isqrt(N) do
       for i from 0 to s/2 do
          t:= i^2 + (s-i)^2;
          if t > N then break fi;
          if not assigned(R[t]) then R[t]:= s fi;
    od od:
    A1481:= sort(map(op, [indices(R)])):
    seq(R[i],i=A1481); # Robert Israel, Oct 28 2019
  • Python
    from itertools import count, islice
    from sympy.solvers.diophantine.diophantine import diop_DN
    from sympy import factorint
    def A328803_gen(): # generator of terms
        return map(lambda n: min((a+b for a, b in diop_DN(-1,n))), filter(lambda n:(lambda m:all(d&3!=3 or m[d]&1==0 for d in m))(factorint(n)), count(0)))
    A328803_list = list(islice(A328803_gen(),30)) # Chai Wah Wu, Sep 09 2022