A323882 -id:A323882 - cp's OEIS frontend

A126760 a(0) = 0, a(2n) = a(n), a(3n) = a(n), a(6n+1) = 2n + 1, a(6n+5) = 2n + 2.

0, 1, 1, 1, 1, 2, 1, 3, 1, 1, 2, 4, 1, 5, 3, 2, 1, 6, 1, 7, 2, 3, 4, 8, 1, 9, 5, 1, 3, 10, 2, 11, 1, 4, 6, 12, 1, 13, 7, 5, 2, 14, 3, 15, 4, 2, 8, 16, 1, 17, 9, 6, 5, 18, 1, 19, 3, 7, 10, 20, 2, 21, 11, 3, 1, 22, 4, 23, 6, 8, 12, 24, 1, 25, 13, 9, 7, 26, 5, 27, 2, 1, 14, 28, 3, 29, 15, 10, 4, 30, 2

Offset: 0

N. J. A. Sloane, Feb 19 2007

nonn

For further information see A126759, which provided the original motivation for this sequence.
From Antti Karttunen, Jan 28 2015: (Start)
The odd bisection of the sequence gives A253887, and the even bisection gives the sequence itself.
A254048 gives the sequence obtained when this sequence is restricted to A007494 (numbers congruent to 0 or 2 mod 3).
For all odd numbers k present in square array A135765, a(k) = the column index of k in that array. (End)
A322026 and this sequence (without the initial zero) are ordinal transforms of each other. - Antti Karttunen, Feb 09 2019
Also ordinal transform of A065331 (after the initial 0). - Antti Karttunen, Sep 08 2024

Antti Karttunen, Table of n, a(n) for n = 0..19683

One less than A126759.
Cf. A003586, A003602, A007310, A064989, A249746, A253887, A254048, A273669, A322317, A323881 (Dirichlet inverse), A323882.
Cf. A347233 (Möbius transform) and also A349390, A349393, A349395 for other Dirichlet convolutions.
Ordinal transform of A065331 and of A322026 (after the initial 0).
Related arrays: A135765, A254102.

f[n_] := Block[{a}, a[0] = 0; a[1] = a[2] = a[3] = 1; a[x_] := Which[EvenQ@ x, a[x/2], Mod[x, 3] == 0, a[x/3], Mod[x, 6] == 1, 2 (x - 1)/6 + 1, Mod[x, 6] == 5, 2 (x - 5)/6 + 2]; Table[a@ i, {i, 0, n}]] (* Michael De Vlieger, Feb 03 2015 *)

A126760(n)={n&&n\=3^valuation(n,3)<M. F. Hasler, Jan 19 2016

a(n) = A126759(n)-1. [The original definition.]
From Antti Karttunen, Jan 28 2015: (Start)
a(0) = 0, a(2n) = a(n), a(3n) = a(n), a(6n+1) = 2n + 1, a(6n+5) = 2n + 2.
Or with the last clause represented in another way:
a(0) = 0, a(2n) = a(n), a(3n) = a(n), a(6n+1) = 2n + 1, a(6n-1) = 2n.
Other identities. For all n >= 1:
a(n) = A253887(A003602(n)).
a(6n-3) = a(4n-2) = a(2n-1) = A253887(n).
(End)
a(n) = A249746(A003602(A064989(n))). - Antti Karttunen, Feb 04 2015
a(n) = A323882(4*n). - Antti Karttunen, Apr 18 2022

Name replaced with an independent recurrence and the old description moved to the Formula section - Antti Karttunen, Jan 28 2015

A349135 Sum of Kimberling's paraphrases (A003602) and its Dirichlet inverse.

Original entry on oeis.org

2, 0, 0, 1, 0, 4, 0, 1, 4, 6, 0, 2, 0, 8, 12, 1, 0, 6, 0, 3, 16, 12, 0, 2, 9, 14, 12, 4, 0, 4, 0, 1, 24, 18, 24, 5, 0, 20, 28, 3, 0, 6, 0, 6, 26, 24, 0, 2, 16, 17, 36, 7, 0, 16, 36, 4, 40, 30, 0, 8, 0, 32, 36, 1, 42, 10, 0, 9, 48, 12, 0, 5, 0, 38, 46, 10, 48, 12, 0, 3, 37, 42, 0, 11, 54, 44, 60, 6, 0, 20, 56, 12

Offset: 1

Antti Karttunen, Nov 13 2021

sign

Question: Are all terms nonnegative?

The answer to the above question is no, because A323894 (which is a prime-shifted version of this sequence) also contains negative values. For example, for n=72747675, 88062975, 130945815, 111035925 we get here a(n) = -14126242, -17546656, -14460312, -22677277. The indices are obtained by prime-shifting with A003961 the four indices mentioned in the Apr 20 2022 comment of A323894. - Antti Karttunen, Nov 30 2024

Antti Karttunen, Table of n, a(n) for n = 1..16384
Antti Karttunen, Data supplement: n, a(n) computed for n = 1..65537

Cf. A003602 (also quadrisection of this sequence), A349134, A323894 [= a(A003961(n))].

Cf. also A323882, A349126.

k[n_] := (n/2^IntegerExponent[n, 2] + 1)/2; d[1] = 1; d[n_] := d[n] = -DivisorSum[n, d[#]*k[n/#] &, # < n &]; a[n_] := k[n] + d[n]; Array[a, 100] (* Amiram Eldar, Nov 13 2021 *)

up_to = 16384;
DirInverseCorrect(v) = { my(u=vector(#v)); u[1] = (1/v[1]); for(n=2, #v, u[n] = (-u[1]*sumdiv(n, d, if(dA003602(n) = (1+(n>>valuation(n,2)))/2;
v349134 = DirInverseCorrect(vector(up_to,n,A003602(n)));
A349134(n) = v349134[n];
A349135(n) = (A003602(n)+A349134(n));

A349135(n) = if(1==n,2,-sumdiv(n, d, if(1==d||n==d,0,A003602(d)*A349134(n/d)))); \\ (Demonstrates the "cut convolution" formula) - Antti Karttunen, Nov 13 2021

A003602(n) = (1+(n>>valuation(n,2)))/2;
memoA349134 = Map();
A349134(n) = if(1==n,1,my(v); if(mapisdefined(memoA349134,n,&v), v, v = -sumdiv(n,d,if(dA003602(n/d)*A349134(d),0)); mapput(memoA349134,n,v); (v)));
A349135(n) = (A003602(n)+A349134(n)); \\ Antti Karttunen, Nov 30 2024

a(n) = A003602(n) + A349134(n).
a(1) = 2, and for n > 1, a(n) = -Sum_{d|n, 1A003602(d) * A349134(n/d).
For all n >= 1, a(4*n) = A003602(n). - Antti Karttunen, Dec 07 2021

A323881 Dirichlet inverse of A126760.

Original entry on oeis.org

1, -1, -1, 0, -2, 1, -3, 0, 0, 2, -4, 0, -5, 3, 2, 0, -6, 0, -7, 0, 3, 4, -8, 0, -5, 5, 0, 0, -10, -2, -11, 0, 4, 6, 0, 0, -13, 7, 5, 0, -14, -3, -15, 0, 0, 8, -16, 0, -8, 5, 6, 0, -18, 0, -3, 0, 7, 10, -20, 0, -21, 11, 0, 0, -2, -4, -23, 0, 8, 0, -24, 0, -25, 13, 5, 0, -2, -5, -27, 0, 0, 14, -28, 0, -5, 15, 10, 0, -30, 0, -1, 0

Offset: 1

Antti Karttunen, Feb 08 2019

sign

Antti Karttunen, Table of n, a(n) for n = 1..20000

Cf. A126760, A323882, A323883, A323886.

b[n_] := b[n] = Which[n == 0, 0, 0 < n < 4, 1, EvenQ[n], b[n/2], Mod[n, 3] == 0, b[n/3], Mod[n, 6] == 1, (n-1)/3 + 1, Mod[n, 6] == 5, (n-5)/3 + 2];
a[n_] := a[n] = If[n == 1, 1, -Sum[b[n/d] a[d], {d, Most@ Divisors[n]}]];
Array[a, 100] (* Jean-François Alcover, Feb 16 2020 *)

up_to = 20000;
DirInverseCorrect(v) = { my(u=vector(#v)); u[1] = (1/v[1]); for(n=2, #v, u[n] = (-u[1])*sumdiv(n, d, if(dA126760(n) = {n&&n\=3^valuation(n, 3)<A126760
v323881 = DirInverseCorrect(vector(up_to,n,A126760(n)));
A323881(n) = v323881[n];

A323885 Sum of A001511 and its Dirichlet inverse.

Original entry on oeis.org

2, 0, 0, 4, 0, 4, 0, 4, 1, 4, 0, 2, 0, 4, 2, 5, 0, 2, 0, 2, 2, 4, 0, 4, 1, 4, 1, 2, 0, 0, 0, 6, 2, 4, 2, 3, 0, 4, 2, 4, 0, 0, 0, 2, 1, 4, 0, 5, 1, 2, 2, 2, 0, 2, 2, 4, 2, 4, 0, 4, 0, 4, 1, 7, 2, 0, 0, 2, 2, 0, 0, 4, 0, 4, 1, 2, 2, 0, 0, 5, 1, 4, 0, 4, 2, 4, 2, 4, 0, 2, 2, 2, 2, 4, 2, 6, 0, 2, 1, 3, 0, 0, 0, 4, 0

Offset: 1

Antti Karttunen, Feb 08 2019

nonn

Antti Karttunen, Table of n, a(n) for n = 1..65537

Cf. A001511, A092673.

Cf. also A318449, A318450, A323365, A323882, A323884, A323887, A323896.

A001511(n) = (1+valuation(n,2));
A092673(n) = (moebius(n)-if(n%2,0,moebius(n/2)));
A323885(n) = (A001511(n)+A092673(n));

from sympy import mobius
def A323885(n): return (n&-n).bit_length()+mobius(n)-(0 if n&1 else mobius(n>>1)) # Chai Wah Wu, Jul 13 2022

a(n) = A001511(n) + A092673(n).

A323887 Sum of Per Nørgård's "infinity sequence" (A004718) and its Dirichlet inverse (A323886).

Original entry on oeis.org

2, 0, 0, 1, 0, -4, 0, -1, 4, 0, 0, 2, 0, -6, 0, 1, 0, 0, 0, 0, 12, -2, 0, -2, 0, 2, 0, 3, 0, -8, 0, -1, 4, 0, 0, 2, 0, -6, -4, 0, 0, 10, 0, 1, 16, -4, 0, 2, 9, -6, 0, -1, 0, 0, 0, -3, 12, 4, 0, 4, 0, -10, -20, 1, 0, 0, 0, 0, 8, -2, 0, -2, 0, 2, 12, 3, 6, -12, 0, 0, -4, -2, 0, 1, 0, -4, -8, -1, 0, 16, -6, 2, 20, -6, 0, -2, 0, 11, 0, 3, 0, -8, 0, 1, 28

Offset: 1

Antti Karttunen, Feb 08 2019

sign

The composer Per Nørgård's name is also written in the OEIS as Per Noergaard.

Antti Karttunen, Table of n, a(n) for n = 1..16384
Antti Karttunen, Data supplement: n, a(n) computed for n = 1..65537

Cf. A004718, A323886.

Cf. also A323365, A323882, A323885, A323896.

up_to = 65537;
A004718list(up_to) = { my(v=vector(up_to)); v[1]=1; v[2]=-1; for(n=3, up_to, v[n] = if(n%2, 1+v[n>>1], -v[n/2])); (v); }; \\ After code in A004718.
DirInverse(v) = { my(u=vector(#v)); u[1] = (1/v[1]); for(n=2, #v, u[n] = -sumdiv(n, d, if(dA004718list(up_to);
A004718(n) = v004718[n];
v323886 = DirInverse(v004718);
A323886(n) = v323886[n];
A323887(n) = (A004718(n)+A323886(n));

a(n) = A004718(n) + A323886(n).

A323884 Sum of A322026 and its Dirichlet inverse.

Original entry on oeis.org

2, 0, 0, 4, 0, 12, 0, 8, 9, 4, 0, 8, 0, 4, 6, 8, 0, 4, 0, 4, 6, 4, 0, 0, 1, 4, 15, 4, 0, -2, 0, 12, 6, 4, 2, 13, 0, 4, 6, 4, 0, -2, 0, 4, 5, 4, 0, 22, 1, 2, 6, 4, 0, 7, 2, 4, 6, 4, 0, 8, 0, 4, 5, 20, 2, -2, 0, 4, 6, 0, 0, 38, 0, 4, 3, 4, 2, -2, 0, 10, 13, 4, 0, 8, 2, 4, 6, 4, 0, 16, 2, 4, 6, 4, 2, 28, 0, 2, 5, 4, 0, -2, 0, 4, 0

Offset: 1

Antti Karttunen, Feb 08 2019

sign

Antti Karttunen, Table of n, a(n) for n = 1..20000
Antti Karttunen, Data supplement: n, a(n) computed for n = 1..65537

Cf. A007814, A007949, A322026, A323882, A323883, A323885.

up_to = 65537;
rgs_transform(invec) = { my(om = Map(), outvec = vector(length(invec)), u=1); for(i=1, length(invec), if(mapisdefined(om,invec[i]), my(pp = mapget(om, invec[i])); outvec[i] = outvec[pp] , mapput(om,invec[i],i); outvec[i] = u; u++ )); outvec; };
A007814(n) = valuation(n,2);
A007949(n) = valuation(n,3);
v322026 = rgs_transform(vector(up_to, n, [A007814(n), A007949(n)]));
A322026(n) = v322026[n];
DirInverse(v) = { my(u=vector(#v)); u[1] = (1/v[1]); for(n=2, #v, u[n] = -sumdiv(n, d, if(dA323883(n) = v323883[n];
A323884(n) = (A322026(n)+A323883(n));

a(n) = A322026(n) + A323883(n).

A353336 Sum of A353420 and its Dirichlet inverse.

Original entry on oeis.org

2, 0, 0, 1, 0, 4, 0, 1, 4, 6, 0, 2, 0, 8, 12, 1, 0, 14, 0, 3, 16, 10, 0, 2, 9, 12, 28, 4, 0, 12, 0, 1, 20, 14, 24, 9, 0, 16, 24, 3, 0, 22, 0, 5, 66, 20, 0, 2, 16, 25, 28, 6, 0, 56, 30, 4, 32, 22, 0, 12, 0, 26, 100, 1, 36, 24, 0, 7, 40, 28, 0, 9, 0, 28, 86, 8, 40, 34, 0, 3, 157, 30, 0, 19, 42, 32, 44, 5, 0, 52, 48

Offset: 1

Antti Karttunen, Apr 20 2022

sign

The first negative term is a(255255) = -11936.

Antti Karttunen, Table of n, a(n) for n = 1..16384
Index entries for sequences computed from indices in prime factorization

Cf. A003961, A126760, A353420 (also a quadrisection of this sequence), A353335.

Cf. also A323882, A323894, A349135.

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(dA003961(n) = { my(f = factor(n)); for(i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); };
A126760(n) = {n&&n\=3^valuation(n, 3)<A126760
A353420(n) = A126760(A003961(n));
v353335 = DirInverseCorrect(vector(up_to,n,A353420(n)));
A353335(n) = v353335[n];
A353336(n) = (A353420(n)+A353335(n));

a(n) = A353420(n) + A353335(n).

For n > 1, a(n) = -Sum_{d|n, 1A353420(d) * A353335(n/d).

A359165 Difference between A126760 and its Möbius transform.

Original entry on oeis.org

0, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 3, 2, 1, 1, 1, 1, 2, 3, 4, 1, 1, 2, 5, 1, 3, 1, 2, 1, 1, 4, 6, 4, 1, 1, 7, 5, 2, 1, 3, 1, 4, 2, 8, 1, 1, 3, 9, 6, 5, 1, 1, 5, 3, 7, 10, 1, 2, 1, 11, 3, 1, 6, 4, 1, 6, 8, 12, 1, 1, 1, 13, 9, 7, 6, 5, 1, 2, 1, 14, 1, 3, 7, 15, 10, 4, 1, 2, 7, 8, 11, 16, 8, 1, 1, 17

Offset: 1

Antti Karttunen, Dec 22 2022

nonn

Antti Karttunen, Table of n, a(n) for n = 1..12000
Antti Karttunen, Data supplement: n, a(n) computed for n = 1..100000

Cf. A008683, A126760, A347233.

Cf. also A323882, A359164.

A126760(n) = {n&&n\=3^valuation(n, 3)<A126760.
A347233(n) = sumdiv(n,d,moebius(n/d)*A126760(d));
A359165(n) = (A126760(n)-A347233(n));

a(n) = A126760(n) - A347233(n).
a(n) = Sum_{d|n, dA347233(d).
a(n) = -Sum_{d|n, dA008683(n/d)*A126760(d).

cp's OEIS Frontend

A126760 a(0) = 0, a(2n) = a(n), a(3n) = a(n), a(6n+1) = 2n + 1, a(6n+5) = 2n + 2.

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A349135 Sum of Kimberling's paraphrases (A003602) and its Dirichlet inverse.

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A323881 Dirichlet inverse of A126760.

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A323885 Sum of A001511 and its Dirichlet inverse.

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A323887 Sum of Per Nørgård's "infinity sequence" (A004718) and its Dirichlet inverse (A323886).

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A323884 Sum of A322026 and its Dirichlet inverse.

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A353336 Sum of A353420 and its Dirichlet inverse.

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A359165 Difference between A126760 and its Möbius transform.

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