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 1-10 of 14 results. Next

A300244 Difference between A005187 and its Möbius transform (A297111).

Original entry on oeis.org

0, 1, 1, 3, 1, 6, 1, 7, 4, 10, 1, 14, 1, 13, 11, 15, 1, 22, 1, 22, 14, 21, 1, 30, 8, 25, 16, 29, 1, 40, 1, 31, 22, 34, 18, 46, 1, 37, 26, 46, 1, 57, 1, 45, 38, 44, 1, 62, 11, 57, 35, 53, 1, 68, 26, 61, 38, 56, 1, 84, 1, 59, 51, 63, 30, 90, 1, 70, 45, 89, 1, 94, 1, 73, 65, 77, 29, 104, 1, 94, 50, 81, 1, 117, 39, 84, 57, 93, 1, 128, 33, 92, 60, 91, 42
Offset: 1

Views

Author

Antti Karttunen, Mar 10 2018

Keywords

Crossrefs

Programs

  • Mathematica
    Table[IntegerExponent[(2 n)!, 2] - DivisorSum[n, IntegerExponent[(2 #)!, 2] MoebiusMu[n/#] &], {n, 95}] (* or *)
    Fold[Function[{a, n}, Append[a, {Abs@ Total@ Map[MoebiusMu[n/#] a[[#, -1]] &, Most@ Divisors@ n], IntegerExponent[(2 n)!, 2]}]], {{0, 1}}, Range[2, 95]][[All, 1]] (* Michael De Vlieger, Mar 10 2018 *)
  • PARI
    A005187(n) = { my(s=n); while(n>>=1, s+=n); s; };
    A300244(n) = -sumdiv(n,d,(dA005187(d));

Formula

a(n) = A005187(n) - A297111(n).
a(n) = -Sum_{d|n, dA008683(n/d)*A005187(d).

A297114 Möbius transform of A294898, where A294898 is deficiency minus binary weight.

Original entry on oeis.org

0, 0, 0, 0, 2, -2, 3, 0, 3, -2, 7, -4, 9, -2, 0, 0, 14, -6, 15, -4, 4, -2, 18, -8, 14, -2, 7, -4, 24, -14, 25, 0, 9, -2, 14, -12, 33, -2, 9, -8, 37, -18, 38, -4, 3, -2, 41, -16, 35, -10, 12, -4, 48, -18, 24, -8, 15, -2, 53, -28, 55, -2, 6, 0, 33, -26, 63, -4, 21, -22, 66, -24, 69, -2, 6, -4, 44, -30, 73, -16, 28, -2
Offset: 1

Views

Author

Antti Karttunen, Dec 26 2017

Keywords

Crossrefs

Programs

  • Mathematica
    Table[DivisorSum[n, MoebiusMu[n/#] (2 # - DigitCount[2 #, 2, 1] - DivisorSigma[1, #]) &], {n, 82}] (* Michael De Vlieger, Mar 11 2019 *)
  • PARI
    A005187(n) = { my(s=n); while(n>>=1, s+=n); s; };
    A297114(n) = sumdiv(n,d,moebius(n/d)*(A005187(d)-sigma(d)));

Formula

a(n) = Sum_{d|n} A008683(n/d)*A294898(d).
a(n) = A297111(n) - n.
a(n) = A297117(n) - A051953(n).
a(n) = A083254(n) - A297115(n).
a(2n) = A083254(2n) = A378986(n) = -2*A176095(n).
a(n) = A294898(n) - A317844(n).

A297117 Möbius transform of A011371, n minus (number of 1's in binary expansion of n).

Original entry on oeis.org

0, 1, 1, 2, 3, 2, 4, 4, 6, 4, 8, 4, 10, 6, 7, 8, 15, 6, 16, 8, 13, 10, 19, 8, 19, 12, 16, 12, 25, 8, 26, 16, 22, 16, 25, 12, 34, 18, 24, 16, 38, 12, 39, 20, 24, 22, 42, 16, 42, 20, 31, 24, 49, 18, 39, 24, 36, 28, 54, 16, 56, 30, 33, 32, 50, 20, 64, 32, 46, 24, 67, 24, 70, 36, 41, 36, 61, 24, 74, 32, 55, 40, 79, 24
Offset: 1

Views

Author

Antti Karttunen, Dec 26 2017

Keywords

Crossrefs

Programs

  • PARI
    A297117(n) = sumdiv(n,d,moebius(n/d)*(d-hammingweight(d)));

Formula

a(n) = Sum_{d|n} A008683(n/d) * (d - A000120(d)).
a(n) = A297111(n) - A000010(n).
a(n) = A297114(n) + A051953(n).

A300724 Möbius transform of A053644(n), largest power of 2 less than or equal to n.

Original entry on oeis.org

1, 1, 1, 2, 3, 1, 3, 4, 6, 3, 7, 2, 7, 3, 3, 8, 15, 6, 15, 6, 11, 7, 15, 4, 12, 7, 8, 6, 15, 3, 15, 16, 23, 15, 25, 12, 31, 15, 23, 12, 31, 11, 31, 14, 18, 15, 31, 8, 28, 12, 15, 14, 31, 8, 21, 12, 15, 15, 31, 6, 31, 15, 10, 32, 53, 23, 63, 30, 47, 25, 63, 24, 63, 31, 44, 30, 53, 23, 63, 24, 48, 31, 63, 22, 45, 31, 47, 28, 63, 18, 53, 30, 47, 31
Offset: 1

Views

Author

Antti Karttunen, Mar 11 2018

Keywords

Crossrefs

Programs

Formula

a(n) = Sum_{d|n} A008683(n/d)*A053644(d).
a(n) + A300725(n) = A000010(n).

A300725 Möbius transform of A053645(n), distance to the largest power of 2 less than or equal to n.

Original entry on oeis.org

0, 0, 1, 0, 1, 1, 3, 0, 0, 1, 3, 2, 5, 3, 5, 0, 1, 0, 3, 2, 1, 3, 7, 4, 8, 5, 10, 6, 13, 5, 15, 0, -3, 1, -1, 0, 5, 3, 1, 4, 9, 1, 11, 6, 6, 7, 15, 8, 14, 8, 17, 10, 21, 10, 19, 12, 21, 13, 27, 10, 29, 15, 26, 0, -5, -3, 3, 2, -3, -1, 7, 0, 9, 5, -4, 6, 7, 1, 15, 8, 6, 9, 19, 2, 19, 11, 9, 12, 25, 6, 19, 14, 13, 15, 27
Offset: 1

Views

Author

Antti Karttunen, Mar 11 2018

Keywords

Crossrefs

Programs

  • Mathematica
    With[{s = Array[# - 2^Floor@ Log2@ # &, 95]}, Table[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
    A053645(n) = (n-A053644(n));
    A300725(n) = sumdiv(n,d,moebius(n/d)*A053645(d));

Formula

a(n) = Sum_{d|n} A008683(n/d)*A053645(d).
a(n) + A300724(n) = A000010(n).

A296208 Xor-Moebius transform of A005187.

Original entry on oeis.org

1, 2, 5, 4, 9, 12, 10, 8, 20, 24, 18, 24, 22, 16, 23, 16, 33, 60, 34, 48, 41, 56, 43, 48, 39, 36, 34, 40, 55, 52, 56, 32, 86, 96, 65, 120, 70, 104, 88, 96, 78, 104, 83, 120, 88, 112, 88, 96, 84, 84, 71, 80, 103, 104, 115, 80, 72, 68, 112, 96, 116, 76, 75, 64, 158, 244, 130, 192, 168, 192, 139, 240, 142, 212, 175, 216
Offset: 1

Views

Author

Antti Karttunen, Dec 25 2017

Keywords

Comments

Unique sequence satisfying SumXOR_{d divides n} a(d) = A005187(n) for all n > 0, where SumXOR is the analog of summation under the binary XOR operation. See A295901 for a list of some of the properties of Xor-Moebius transform. A297111 gives the ordinary Möbius transform of A005187.

Crossrefs

Programs

  • PARI
    A005187(n) = { my(s=n); while(n>>=1, s+=n); s; };
    A296208(n) = { my(v=0); fordiv(n, d, if(issquarefree(n/d), v=bitxor(v, A005187(d)))); (v); } \\ after code in A295901.

A300723 Möbius-transform of A005187(A053645(n)).

Original entry on oeis.org

0, 0, 1, 0, 1, 2, 4, 0, 0, 2, 4, 4, 8, 6, 9, 0, 1, 0, 4, 4, 3, 6, 11, 8, 15, 10, 18, 12, 23, 10, 26, 0, -4, 2, -1, 0, 8, 6, 2, 8, 16, 2, 19, 12, 12, 14, 26, 16, 28, 16, 33, 20, 39, 20, 37, 24, 42, 26, 50, 20, 54, 30, 49, 0, -8, -6, 4, 4, -4, -2, 11, 0, 16, 10, -7, 12, 15, 2, 26, 16, 13, 18, 35, 4, 37, 22, 18, 24, 47, 12
Offset: 1

Views

Author

Antti Karttunen, Mar 12 2018

Keywords

Crossrefs

Programs

  • Mathematica
    With[{s = Array[2 # - DigitCount[2 #, 2, 1] &[# - 2^Floor@ Log2@ #] &, 90]}, Table[DivisorSum[n, MoebiusMu[n/#] s[[#]] &], {n, Length@ s}]] (* Michael De Vlieger, Mar 13 2018 *)
  • PARI
    A005187(n) = { my(s=n); while(n>>=1, s+=n); s; };
    A053644(n) = { my(k=1); while(k<=n, k<<=1); (k>>1); }; \\ From A053644
    A053645(n) = (n-A053644(n));
    A300723(n) = sumdiv(n,d,moebius(n/d)*A005187(A053645(d)));

Formula

a(n) = Sum_{d|n} A008683(n/d)*A005187(A053645(d)).
a(1) = 0; for n > 1, a(n) = A297111(n) - 2*A300724(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.

A324397 a(1) = 0; for n > 1, a(n) = A297114(A156552(n)).

Original entry on oeis.org

0, 0, 0, 0, 0, 2, 0, 3, -2, 3, 0, 7, 0, 14, -2, 0, 0, 9, 0, 15, -6, 9, 0, 18, -4, 33, -2, 14, 0, 4, 0, 25, -2, 42, -4, 7, 0, 254, -26, 9, 0, 33, 0, 63, -2, 140, 0, 41, -8, 14, -34, 127, 0, 24, -12, 66, -90, 579, 0, 38, 0, 684, -2, 6, -4, 21, 0, 175, -2, 37, 0, 24, 0, 3587, -2, 304, -8, 85, 0, 73, -14, 2733, 0, 6, -52, 8707, -378, 11, 0, 3
Offset: 1

Views

Author

Antti Karttunen, Mar 05 2019

Keywords

Crossrefs

Programs

  • Mathematica
    Array[If[# == 1, 0, Function[n, DivisorSum[n, MoebiusMu[n/#] (2 # - DigitCount[2 #, 2, 1] - DivisorSigma[1, #]) &]]@ Floor@ Total@ Flatten@ MapIndexed[#1 2^(#2 - 1) &, Flatten[Table[2^(PrimePi@ #1 - 1), {#2}] & @@@ FactorInteger@ #]]] &, 90] (* Michael De Vlieger, Mar 11 2019 *)
  • PARI
    A064989(n) = {my(f); f = factor(n); if((n>1 && f[1,1]==2), f[1,2] = 0); for (i=1, #f~, f[i,1] = precprime(f[i,1]-1)); factorback(f)};
    A156552(n) = if(1==n, 0, if(!(n%2), 1+(2*A156552(n/2)), 2*A156552(A064989(n))));
    A005187(n) = { my(s=n); while(n>>=1, s+=n); s; };
    \\ Slow: A297114(n) = sumdiv(n,d,moebius(n/d)*(A005187(d)-sigma(d)));
    A297111(n) = sumdiv(n,d,moebius(n/d)*A005187(d));
    A297114(n) = (A297111(n) - n);
    A324397(n) = if(1==n,0,A297114(A156552(n)));

Formula

a(1) = 0; for n > 1, a(n) = A297114(A156552(n)).
For all n >= 1, a(2n-1) = A324103(2n-1).
Showing 1-10 of 14 results. Next