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 1-9 of 9 results.

A086962 a(A086957(n))=A086957(n), a(A086958(n))=A086959(n), a(A086959(n))=A086958(n), see A086956.

Original entry on oeis.org

1, 3, 2, 4, 5, 8, 7, 6, 9, 25, 11, 15, 13, 21, 12, 16, 17, 18, 19, 24, 14, 33, 23, 20, 10, 39, 27, 28, 29, 36, 31, 32, 22, 51, 35, 30, 37, 57, 26, 48, 41, 56, 43, 44, 54, 69, 47, 40, 49, 50, 34, 52, 53, 45, 55, 42, 38, 87, 59, 70, 61, 93, 63, 64, 65, 88, 67, 68, 46
Offset: 1

Views

Author

Reinhard Zumkeller, Jul 25 2003

Keywords

Comments

A self-inverse permutation of natural numbers: a(a(n))=n;
a(n) = A086962(A086963(n)) = A086963(A086962(n)).

Crossrefs

A086963 a(A086957(n))=A086959(n), a(A086958(n))=A086958(n), a(A086959(n))=A086957(n), see A086956.

Original entry on oeis.org

3, 2, 1, 8, 25, 6, 21, 4, 15, 10, 33, 12, 39, 14, 9, 24, 51, 36, 57, 20, 7, 22, 69, 16, 5, 26, 54, 56, 87, 30, 93, 48, 11, 34, 280, 18, 111, 38, 13, 40, 123, 42, 129, 88, 45, 46, 141, 32, 343, 70, 17, 104, 159, 27, 275, 28, 19, 58, 177, 60, 183, 62, 168, 112, 325
Offset: 1

Views

Author

Reinhard Zumkeller, Jul 25 2003

Keywords

Comments

A self-inverse permutation of natural numbers: a(a(n))=n;
a(n) = A086962(A086963(n)) = A086963(A086962(n)).

Crossrefs

A086957 Smallest m with A086956(m)=n.

Original entry on oeis.org

1, 4, 9, 16, 5, 18, 7, 32, 27, 50, 11, 72, 13, 28, 75, 64, 17, 108, 19, 100, 63, 44, 23, 192, 125, 52, 81, 196, 29, 180, 31, 128, 99, 68, 35, 288, 37, 76, 117, 200, 41, 294, 43, 176, 225, 92, 47, 384, 49, 250, 153, 208, 53, 486, 55, 392, 171, 116, 59, 420, 61
Offset: 1

Views

Author

Reinhard Zumkeller, Jul 25 2003

Keywords

Comments

a(n) < A086958(n) < A086959(n), A086956(a(n))=A086956(A086958(n))=A086956(A086959(n));
n and A086956(n) are divisors of a(n);
A086960(a(n)) = A086958(n), A086960(A086959(n)) = a(n);
A086961(a(n)) = A086959(n), A086961(A086958(n)) = a(n);
A086962(a(n)) = a(n);
A086963(a(n)) = A086959(n), A086963(A086959(n)) = a(n);
A086964(a(n)) = A086958(n), A086964(A086958(n)) = a(n).

Crossrefs

A086958 m such that A086956(m)=n and A086956(k)=n for exactly one kA086957(n)).

Original entry on oeis.org

2, 6, 12, 20, 10, 30, 14, 40, 45, 60, 22, 84, 26, 42, 90, 80, 34, 126, 38, 120, 147, 66, 46, 216, 150, 78, 135, 224, 58, 210, 62, 160, 132, 102, 245, 324, 74, 114, 156, 320, 82, 336, 86, 220, 315, 138, 94, 432, 98, 300, 204, 260, 106, 540, 110, 448, 228, 174
Offset: 1

Views

Author

Reinhard Zumkeller, Jul 25 2003

Keywords

Comments

A086957(n) < a(n) < A086959(n), A086956(a(n))=A086956(A086957(n))=A086956(A086959(n));
n and A086956(n) are divisors of a(n);
A086960(A086957(n)) = a(n), A086960(a(n)) = A086959(n);
A086961(a(n)) = A086957(n), A086961(A086959(n)) = a(n);
A086962(a(n)) = A086959(n), A086962(A086959(n)) = a(n);
A086963(a(n)) = a(n);
A086964(A086957(n)) = a(n), A086964(a(n)) = A086957(n).

Crossrefs

A086959 Greatest m with A086956(m)=n.

Original entry on oeis.org

3, 8, 15, 24, 25, 36, 21, 48, 54, 70, 33, 96, 39, 56, 105, 112, 51, 144, 57, 140, 168, 88, 69, 240, 175, 104, 162, 252, 87, 270, 93, 256, 165, 136, 280, 360, 111, 152, 195, 400, 123, 378, 129, 264, 405, 184, 141, 480, 343, 350, 255, 312, 159, 594, 275, 504
Offset: 1

Views

Author

Reinhard Zumkeller, Jul 25 2003

Keywords

Comments

A086957(n) < A086958(n) < a(n), A086956(a(n))=A086956(A086957(n))=A086956(A086958(n));
n and A086956(n) are divisors of a(n);
A086960(A086958(n)) = a(n), A086960(a(n)) = A086957(n);
A086961(A086957(n)) = a(n), A086961(a(n)) = A086958(n);
A086962(A086958(n)) = a(n), A086962(a(n)) = A086958(n);
A086963(A086957(n)) = a(n), A086963(a(n)) = A086957(n);
A086964(a(n)) = a(n).

Crossrefs

A086960 a(A086957(n))=A086958(n), a(A086958(n))=A086959(n), a(A086959(n))=A086957(n), see A086956.

Original entry on oeis.org

2, 3, 1, 6, 10, 8, 14, 4, 12, 25, 22, 15, 26, 21, 9, 20, 34, 30, 38, 24, 7, 33, 46, 16, 5, 39, 45, 42, 58, 36, 62, 40, 11, 51, 245, 18, 74, 57, 13, 48, 82, 56, 86, 66, 54, 69, 94, 32, 98, 60, 17, 78, 106, 27, 110, 28, 19, 87, 118, 70, 122, 93, 147, 80, 130, 88, 134
Offset: 1

Views

Author

Reinhard Zumkeller, Jul 25 2003

Keywords

Comments

permutation of natural numbers with inverse A086961: a(A086961(n)) = A086961(a(n)) = n;
a(n) = A086962(A086963(n)) = A086963(A086962(n)).

Crossrefs

A086961 a(A086957(n))=A086959(n), a(A086958(n))=A086957(n), a(A086959(n))=A086958(n), see A086956.

Original entry on oeis.org

3, 1, 2, 8, 25, 4, 21, 6, 15, 5, 33, 9, 39, 7, 12, 24, 51, 36, 57, 16, 14, 11, 69, 20, 10, 13, 54, 56, 87, 18, 93, 48, 22, 17, 280, 30, 111, 19, 26, 32, 123, 28, 129, 88, 27, 23, 141, 40, 343, 70, 34, 104, 159, 45, 275, 42, 38, 29, 177, 50, 183, 31, 168, 112, 325
Offset: 1

Views

Author

Reinhard Zumkeller, Jul 25 2003

Keywords

Comments

permutation of natural numbers with inverse A086960: a(A086960(n)) = A086960(a(n)) = n;
a(n) = A086962(A086963(n)) = A086963(A086962(n)).

Crossrefs

A086964 a(A086957(n))=A086958(n), a(A086958(n))=A086957(n), a(A086959(n))=A086959(n), see A086956.

Original entry on oeis.org

2, 1, 3, 6, 10, 4, 14, 8, 12, 5, 22, 9, 26, 7, 15, 20, 34, 30, 38, 16, 21, 11, 46, 24, 25, 13, 45, 42, 58, 18, 62, 40, 33, 17, 245, 36, 74, 19, 39, 32, 82, 28, 86, 66, 27, 23, 94, 48, 98, 60, 51, 78, 106, 54, 110, 56, 57, 29, 118, 50, 122, 31, 147, 80, 130, 44, 134
Offset: 1

Views

Author

Reinhard Zumkeller, Jul 25 2003

Keywords

Comments

A self-inverse permutation of natural numbers: a(a(n))=n;
a(n) = A086962(A086963(n)) = A086963(A086962(n)).

Crossrefs

A068101 a(n) = Sum_{k|n, k<=sqrt(n)} mu(k) where mu(k) is the Moebius function and the sum is over the positive divisors k of n with k <= sqrt(n).

Original entry on oeis.org

1, 1, 1, 0, 1, 0, 1, 0, 0, 0, 1, -1, 1, 0, 0, 0, 1, -1, 1, 0, 0, 0, 1, -1, 0, 0, 0, 0, 1, -2, 1, 0, 0, 0, 0, 0, 1, 0, 0, -1, 1, 0, 1, 0, -1, 0, 1, 0, 0, -1, 0, 0, 1, 0, 0, -1, 0, 0, 1, -1, 1, 0, -1, 0, 0, 0, 1, 0, 0, -2, 1, 0, 1, 0, -1, 0, 0, 0, 1, -1, 0, 0, 1, -1, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 1, 0, 1
Offset: 1

Views

Author

Leroy Quet, Mar 22 2002

Keywords

Crossrefs

Cf. A086956.

Programs

  • Haskell
    a068101 = sum . map a008683 . a161906_row
    -- Reinhard Zumkeller, Jul 30 2013
    
  • Mathematica
    Table[DivisorSum[n, MoebiusMu, # <= Sqrt[n] &], {n, 103}] (* Michael De Vlieger, Sep 24 2017 *)
  • PARI
    a(n) = sumdiv(n, k, (k<=sqrt(n))*moebius(k)); \\ Michel Marcus, Jan 03 2017

Formula

a(n) = Sum_{k=1..A038548(n)} A008683(A161906(n,k)). - Reinhard Zumkeller, Jul 30 2013
G.f.: Sum_{k>=1} mu(k)*x^(k^2)/(1 - x^k). - Ilya Gutkovskiy, Jan 03 2017
Showing 1-9 of 9 results.