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.

A132352 Partial sums of A132351.

Original entry on oeis.org

1, 3, 6, 9, 13, 18, 24, 30, 36, 43, 51, 60, 70, 81, 93, 105, 118, 132, 147, 163, 180, 198, 217, 237, 257, 278, 299, 321, 344, 368, 393, 418, 444, 471, 499, 527, 556, 586, 617, 649, 682, 716, 751, 787, 824, 862, 901, 941, 981, 1022, 1064, 1107, 1151, 1196, 1242, 1289, 1337
Offset: 1

Views

Author

N. J. A. Sloane, Nov 11 2007

Keywords

Crossrefs

Cf. A132349-A132351, A132384.

A132350 If n > 1 is a k-th power with k >= 2 then a(n) = 0, otherwise a(n) = 1.

Original entry on oeis.org

1, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0
Offset: 1

Views

Author

N. J. A. Sloane, Nov 11 2007

Keywords

Examples

			a(4) = 0 because 4 = 2^2.
a(8) = 0 because 8 = 2^3.
a(12) = 1 because 12 is not a perfect power (though it is divisible by a perfect power).

Links

Crossrefs

Cf. A132349, A132351, A132352, A075802, A001597.

Programs

  • Haskell
    a132350 1 = 1
a132350 n = 1 - a075802 n  -- Reinhard Zumkeller, Jun 14 2013
  • Mathematica
    Table[Boole[GCD@@FactorInteger[n][[All, 2]] == 1], {n, 100}] (* Alonso del Arte, May 28 2018 *)
  • PARI
    (a(n)=!ispower(n)); (r(nMax) = for(j=1,nMax,print1(!ispower(j)","))); r(100)

Formula

a(n) = 1 - A075802(n) for n >= 2. - R. J. Mathar, Nov 12 2007
Given the Möbius function mu(n) = A008683(n), a(n) = abs(mu(n)) unless n is in A303946. - Alonso del Arte, May 28 2018

Extensions

Edited by M. F. Hasler, Jun 01 2018

A132349 If n is a k-th power with k >= 2 then a(n) = k, otherwise a(n) = 0.

Original entry on oeis.org

0, 0, 0, 2, 0, 0, 0, 3, 2, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 3, 0, 0, 0, 0, 5, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 6, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2
Offset: 1

Views

Author

N. J. A. Sloane, Nov 11 2007

Keywords

Links

Crossrefs

Cf. A132350, A132351, A132352, A132384.

Programs

  • Mathematica
    a[n_] := Boole[(g = GCD @@ FactorInteger[n][[;;,2]]) > 1] * g; Array[a, 100] (* Amiram Eldar, Aug 13 2024 *)
  • PARI
    r(n) = for(j=1,n,print1(ispower(j)","));
r(100)
Showing 1-3 of 3 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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