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 1-7 of 7 results.

A297111 Möbius transform of A005187, where A005187(n) = 2n - (number of 1's in binary representation of n).

Original entry on oeis.org

1, 2, 3, 4, 7, 4, 10, 8, 12, 8, 18, 8, 22, 12, 15, 16, 31, 12, 34, 16, 25, 20, 41, 16, 39, 24, 34, 24, 53, 16, 56, 32, 42, 32, 49, 24, 70, 36, 48, 32, 78, 24, 81, 40, 48, 44, 88, 32, 84, 40, 63, 48, 101, 36, 79, 48, 72, 56, 112, 32, 116, 60, 69, 64, 98, 40, 130, 64, 90, 48, 137, 48, 142, 72, 81, 72, 121, 48, 152, 64
Offset: 1

Views

Author

Antti Karttunen, Dec 25 2017

Keywords

Comments

Sequence differs from A035532 for the first time at n = 15, 21, 25, 27, 33, 35, 51, etc., i.e., at those composite n where A297115 has a nonzero value. - Antti Karttunen & M. F. Hasler, Mar 10 2018

Crossrefs

Programs

  • Mathematica
    Table[DivisorSum[n, IntegerExponent[(2 #)!, 2] MoebiusMu[n/#] &], {n, 80}] (* Michael De Vlieger, Mar 10 2018 *)
  • PARI
    A005187(n) = { my(s=n); while(n>>=1, s+=n); s; };
    A297111(n) = sumdiv(n,d,moebius(n/d)*A005187(d));

Formula

a(n) = Sum_{d|n} A005187(d)*A008683(n/d).
a(n) = n + A297114(n).
From Antti Karttunen, Mar 11 2018: (Start)
Sum A005187(n) x^n = Sum a(n)*x^n/(1-x^n). [Another way of saying that this is the Möbius transform of A005187. This was originally included in A035532 by mistake.]
a(n) = 2*phi(n) - A297115(n) = phi(n) + A297117(n).
a(n) = A005187(n) - A300244(n).
a(1) = 1; for n > 1, a(n) = A300723(n) + 2*A300724(n).
(End)

A317844 Difference between A294898 and its Möbius transform (A297114).

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, -2, 0, 3, 2, 0, 0, 1, 0, 0, 3, 7, 0, -6, 2, 9, 3, 1, 0, -2, 0, 0, 7, 14, 5, -9, 0, 15, 9, -4, 0, 3, 0, 5, 5, 18, 0, -14, 3, 14, 14, 7, 0, 2, 9, -3, 15, 24, 0, -24, 0, 25, 10, 0, 11, 12, 0, 12, 18, 15, 0, -29, 0, 33, 16, 13, 10, 14, 0, -12, 10, 37, 0, -23, 16, 38, 24, 1, 0, -16, 12, 16, 25
Offset: 1

Views

Author

Antti Karttunen, Aug 09 2018

Keywords

Crossrefs

Programs

  • PARI
    A005187(n) = { my(s=n); while(n>>=1, s+=n); s; };
    A317844(n) = -sumdiv(n,d,(dA005187(d)-sigma(d)));

Formula

a(n) = -Sum_{d|n, dA008683(n/d)*A294898(d).
a(n) = A294898(n) - A297114(n).
a(n) = A300244(n) - A001065(n).

A317927 Numerators of rational valued sequence whose Dirichlet convolution with itself yields A005187.

Original entry on oeis.org

1, 3, 2, 19, 4, 2, 11, 63, 6, 3, 19, 13, 23, 17, 5, 867, 16, 4, 35, 5, 17, 25, 21, 11, 31, 29, 13, 113, 27, 13, 57, 3069, 13, 9, 23, 25, 71, 41, 14, 69, 79, 33, 41, 169, 9, 25, 89, 615, 259, 53, 17, 197, 51, 25, 29, 389, 20, 31, 113, 59, 117, 67, 10, 22199, 18, 14, 131, 31, 51, 71, 69, 11, 143, 77, 22, 281, 91, 35, 153, 489, 71, 85, 81, 151, 19
Offset: 1

Views

Author

Antti Karttunen, Aug 11 2018

Keywords

Comments

The first negative term is a(330) = -21.

Crossrefs

Cf. A005187, A317928 (denominators).

Programs

Formula

a(n) = numerator of f(n), where f(1) = 1, f(n) = (1/2) * (A005187(n) - Sum_{d|n, d>1, d 1.

A317928 Denominators of rational valued sequence whose Dirichlet convolution with itself yields A005187.

Original entry on oeis.org

1, 2, 1, 8, 1, 1, 2, 16, 1, 1, 2, 4, 2, 4, 1, 128, 1, 1, 2, 1, 2, 4, 1, 2, 2, 4, 1, 16, 1, 2, 2, 256, 1, 1, 2, 4, 2, 4, 1, 8, 2, 4, 1, 16, 1, 2, 2, 64, 8, 4, 1, 16, 1, 2, 2, 32, 1, 2, 2, 8, 2, 4, 1, 1024, 1, 1, 2, 2, 2, 4, 1, 1, 2, 4, 1, 16, 4, 2, 2, 32, 2, 4, 1, 16, 1, 2, 2, 32, 1, 2, 4, 8, 2, 4, 1, 64, 2, 16, 1, 16, 1, 2, 2, 32, 2
Offset: 1

Views

Author

Antti Karttunen, Aug 11 2018

Keywords

Crossrefs

Cf. A005187, A317927 (numerators).

Programs

Formula

a(n) = denominator of f(n), where f(1) = 1, f(n) = (1/2) * (A005187(n) - Sum_{d|n, d>1, d 1.

A318446 Inverse Möbius transform of A005187: a(n) = Sum_{d|n} A005187(d).

Original entry on oeis.org

1, 4, 5, 11, 9, 18, 12, 26, 21, 30, 20, 47, 24, 40, 39, 57, 33, 68, 36, 75, 55, 64, 43, 108, 56, 76, 71, 100, 55, 126, 58, 120, 88, 102, 87, 167, 72, 112, 102, 168, 80, 174, 83, 156, 141, 134, 90, 233, 107, 174, 135, 184, 103, 222, 133, 224, 150, 170, 114, 309, 118, 180, 191, 247, 160, 272, 132, 243, 182, 270, 139, 370, 144
Offset: 1

Views

Author

Antti Karttunen, Aug 26 2018

Keywords

Crossrefs

Cf. also A297111, A300244.

Programs

Formula

a(n) = Sum_{d|n} A005187(d).
a(n) = A005187(n) + A318445(n).
a(n) = A318448(n) + A007429(n).

A300726 Difference between A053644 (the largest power of 2 less than or equal to n) and its Möbius transform.

Original entry on oeis.org

0, 1, 1, 2, 1, 3, 1, 4, 2, 5, 1, 6, 1, 5, 5, 8, 1, 10, 1, 10, 5, 9, 1, 12, 4, 9, 8, 10, 1, 13, 1, 16, 9, 17, 7, 20, 1, 17, 9, 20, 1, 21, 1, 18, 14, 17, 1, 24, 4, 20, 17, 18, 1, 24, 11, 20, 17, 17, 1, 26, 1, 17, 22, 32, 11, 41, 1, 34, 17, 39, 1, 40, 1, 33, 20, 34, 11, 41, 1, 40, 16, 33, 1, 42, 19, 33, 17, 36, 1, 46, 11, 34, 17, 33, 19
Offset: 1

Views

Author

Antti Karttunen, Mar 11 2018

Keywords

Crossrefs

Programs

  • Mathematica
    With[{s = Array[2^Floor@ Log2@ # &, 95]}, Table[s[[n]] - DivisorSum[n, MoebiusMu[n/#] s[[#]] &], {n, Length@ s}]] (* Michael De Vlieger, Mar 13 2018 *)
  • PARI
    A053644(n) = { my(k=1); while(k<=n, k<<=1); (k>>1); }; \\ From A053644
    A300726(n) = -sumdiv(n,d,(dA053644(d));

Formula

a(n) = -Sum_{d|n, dA008683(n/d)*A053644(d).
a(n) = A053644(n) - A300724(n).

A346238 Sum of A005187 and its Dirichlet inverse.

Original entry on oeis.org

2, 0, 0, 9, 0, 24, 0, 15, 16, 48, 0, 8, 0, 66, 64, 31, 0, 32, 0, 4, 88, 114, 0, 50, 64, 138, 64, 7, 0, -116, 0, 63, 152, 192, 176, 80, 0, 210, 184, 90, 0, -138, 0, -1, 80, 252, 0, 94, 121, -6, 256, -5, 0, 28, 304, 125, 280, 324, 0, 390, 0, 342, 136, 127, 368, -276, 0, -20, 336, -386, 0, 126, 0, 426, 24, -17, 418, -360, 0
Offset: 1

Views

Author

Antti Karttunen, Jul 13 2021

Keywords

Crossrefs

Cf. also A300244.

Programs

  • PARI
    up_to = 65537;
    DirInverseCorrect(v) = { my(u=vector(#v)); u[1] = (1/v[1]); for(n=2, #v, u[n] = (-u[1]*sumdiv(n, d, if(dA005187(n) = { my(s=n); while(n>>=1, s+=n); s; };
    v346237 = DirInverseCorrect(vector(up_to,n,A005187(n)));
    A346237(n) = v346237[n];
    A346238(n) = (A005187(n)+A346237(n));

Formula

a(n) = A005187(n) + A346237(n).
Showing 1-7 of 7 results.