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.

Showing 1-3 of 3 results.

A332935 Sum of ceiling(n^(3/2)) where d runs through the divisors of n.

Original entry on oeis.org

1, 4, 7, 12, 13, 25, 20, 35, 34, 48, 38, 75, 48, 76, 78, 99, 72, 129, 84, 146, 123, 145, 112, 216, 138, 184, 175, 233, 158, 293, 174, 281, 234, 274, 240, 395, 227, 322, 298, 422, 264, 467, 283, 445, 407, 427, 324, 613, 363, 527, 443, 567, 387, 667, 458, 676
Offset: 1

Views

Author

Harvey P. Dale, Mar 02 2020

Keywords

Crossrefs

Programs

  • Maple
    a:= n-> add(ceil(d^(3/2)), d=numtheory[divisors](n)):
    seq(a(n), n=1..60);  # Alois P. Heinz, Mar 02 2020
  • Mathematica
    Table[DivisorSum[n,Ceiling[Sqrt[#^3]]&],{n,80}]
  • PARI
    a(n)={sumdiv(n, d, 1 + sqrtint(d^3 - 1))} \\ Andrew Howroyd, Mar 02 2020
    
  • Python
    from math import isqrt
    from sympy import divisors
    def A332935(n): return sum(1+isqrt(d**3-1) for d in divisors(n,generator=True)) # Chai Wah Wu, Aug 03 2022

A058269 An approximation to sigma_{3/2}(n): floor( sum_{d|n} d^(3/2) ).

Original entry on oeis.org

1, 3, 6, 11, 12, 23, 19, 34, 33, 46, 37, 73, 47, 74, 75, 98, 71, 127, 83, 144, 120, 143, 111, 213, 137, 183, 173, 230, 157, 288, 173, 279, 232, 272, 237, 392, 226, 320, 296, 419, 263, 463, 282, 443, 404, 426, 323, 610, 362, 525, 440, 566, 386
Offset: 1

Views

Author

N. J. A. Sloane, Dec 08 2000

Keywords

Crossrefs

Programs

  • Maple
    f := proc(n) local d, t1, t2; t2 := 0; t1 := divisors(n); for d in t1 do t2 := t2 + d^(3/2) end do; t2; end proc; # exact value of sigma_{3/2}(n)
  • Mathematica
    a[n_] := Floor[DivisorSigma[3/2, n]]; Array[a, 50] (* Amiram Eldar, Jan 14 2023 *)

Formula

Sum_{k=1..n} a(k) ~ (2/5)*zeta(5/2) * n^(5/2). - Amiram Eldar, Jan 14 2023

A058270 An approximation to sigma_{3/2}(n): round( sum_{d|n} d^(3/2) ).

Original entry on oeis.org

1, 4, 6, 12, 12, 24, 20, 34, 33, 47, 37, 73, 48, 75, 75, 98, 71, 127, 84, 144, 121, 144, 111, 213, 137, 183, 173, 231, 157, 289, 174, 279, 232, 272, 238, 393, 226, 321, 297, 420, 264, 463, 283, 443, 404, 426, 323, 610, 363, 525, 441, 566, 387
Offset: 1

Views

Author

N. J. A. Sloane, Dec 08 2000

Keywords

Crossrefs

Programs

  • Maple
    f := proc(n) local d, t1, t2; t2 := 0; t1 := divisors(n); for d in t1 do t2 := t2 + d^(3/2) end do; t2; end proc; # exact value of sigma_{3/2}(n)
  • Mathematica
    a[n_] := Round[DivisorSigma[3/2, n]]; Array[a, 50] (* Amiram Eldar, Jan 14 2023 *)

Formula

Sum_{k=1..n} a(k) ~ (2/5)*zeta(5/2) * n^(5/2). - Amiram Eldar, Jan 14 2023
Showing 1-3 of 3 results.