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.

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A269374 Permutation of natural numbers: a(1) = 1, a(n) = A255551(A001511(n), a(A003602(n))) - 1.

Original entry on oeis.org

1, 2, 3, 6, 5, 4, 11, 8, 9, 10, 7, 18, 21, 28, 15, 12, 17, 22, 19, 38, 13, 16, 35, 26, 41, 58, 55, 102, 29, 40, 23, 14, 33, 46, 43, 80, 37, 52, 75, 56, 25, 34, 31, 60, 69, 100, 51, 44, 81, 118, 115, 206, 109, 160, 203, 152, 57, 82, 79, 144, 45, 64, 27, 20, 65, 94, 91, 164, 85, 124, 159, 120, 73, 106, 103, 186, 149, 220, 111, 96, 49
Offset: 1

Views

Author

Antti Karttunen, Mar 01 2016

Keywords

Comments

Permutation obtained from the Lucky sieve.
This sequence can be represented as a binary tree. For n > 2, each left hand child is obtained by doubling the contents of the parent node and subtracting one, and each right hand child is obtained by applying A269372(n), when the parent node contains n:
1
|
...................2...................
3 6
5......../ \........4 11......../ \........8
/ \ / \ / \ / \
/ \ / \ / \ / \
/ \ / \ / \ / \
9 10 7 18 21 28 15 12
17 22 19 38 13 16 35 26 41 58 55 102 29 40 23 14
etc.

Crossrefs

Inverse: A269373.
Cf. also A269375, A269377 and also A249814, A269384.

Formula

a(1) = 1, a(n) = A255551(A001511(n), a(A003602(n))) - 1.
a(1) = 1, a(2n) = A269372(a(n)), a(2n+1) = (2*a(n+1))-1.
Other identities. For all n >= 0:
A000035(a(n)) = A000035(n). [This permutation preserves the parity of n.]

A269384 Permutation of natural numbers: a(1) = 1, a(n) = A255127(A001511(n), a(A003602(n))) - 1.

Original entry on oeis.org

1, 2, 3, 4, 5, 8, 7, 6, 9, 14, 15, 18, 13, 20, 11, 10, 17, 26, 27, 34, 29, 44, 35, 30, 25, 38, 39, 48, 21, 32, 19, 12, 33, 50, 51, 64, 53, 80, 67, 58, 57, 86, 87, 108, 69, 104, 59, 54, 49, 74, 75, 94, 77, 116, 95, 84, 41, 62, 63, 78, 37, 56, 23, 16, 65, 98, 99, 124, 101, 152, 127, 112, 105, 158, 159, 198, 133, 200
Offset: 1

Views

Author

Antti Karttunen, Mar 01 2016

Keywords

Comments

Permutation obtained from the Ludic sieve.
This sequence can be represented as a binary tree. For n > 2, each left hand child is obtained by doubling the contents of the parent node and subtracting one, and each right hand child is obtained by applying A269382(n), when the parent node contains n:
1
|
...................2...................
3 4
5......../ \........8 7......../ \........6
/ \ / \ / \ / \
/ \ / \ / \ / \
/ \ / \ / \ / \
9 14 15 18 13 20 11 10
17 26 27 34 29 44 35 30 25 38 39 48 21 32 19 12
etc.

Crossrefs

Inverse: A269383.
Cf. also A269385, A269387 and also A249814, A269374.

Formula

a(1) = 1, a(n) = A255127(A001511(n), a(A003602(n))) - 1.
a(1) = 1, a(2n) = A269382(a(n)), a(2n+1) = (2*a(n+1))-1.
Other identities. For all n >= 0:
A000035(a(n)) = A000035(n). [This permutation preserves the parity of n.]

A347957 Dirichlet convolution of A001221 (omega) with A003602 (Kimberling's paraphrases).

Original entry on oeis.org

0, 1, 1, 2, 1, 5, 1, 3, 3, 6, 1, 9, 1, 7, 7, 4, 1, 14, 1, 11, 8, 9, 1, 13, 4, 10, 8, 13, 1, 28, 1, 5, 10, 12, 9, 25, 1, 13, 11, 16, 1, 34, 1, 17, 22, 15, 1, 17, 5, 25, 13, 19, 1, 38, 11, 19, 14, 18, 1, 49, 1, 19, 26, 6, 12, 46, 1, 23, 16, 44, 1, 36, 1, 22, 31, 25, 12, 52, 1, 21, 22, 24, 1, 60, 14, 25, 19, 25, 1, 86
Offset: 1

Views

Author

Antti Karttunen, Sep 20 2021

Keywords

Crossrefs

Programs

Formula

a(n) = Sum_{d|n} A001221(n/d) * A003602(d).
From Antti Karttunen, Nov 13 2021: (Start)
The following two convolutions were found by Jon Maiga's Sequence Machine search algorithm. The first one is obvious, and even the second one should not be too hard to prove:
a(n) = Sum_{d|n} A023900(n/d) * A347956(d).
a(n) = Sum_{d|n} A181988(n/d) * A205745(d).
(End)

A349346 Dirichlet inverse of A181988, where A181988(n) = A001511(n)*A003602(n).

Original entry on oeis.org

1, -2, -2, 1, -3, 4, -4, 0, -1, 6, -6, -2, -7, 8, 4, 0, -9, 2, -10, -3, 5, 12, -12, 0, -4, 14, -2, -4, -15, -8, -16, 0, 7, 18, 6, -1, -19, 20, 8, 0, -21, -10, -22, -6, 3, 24, -24, 0, -9, 8, 10, -7, -27, 4, 8, 0, 11, 30, -30, 4, -31, 32, 4, 0, 9, -14, -34, -9, 13, -12, -36, 0, -37, 38, 8, -10, 9, -16, -40, 0, -4, 42
Offset: 1

Views

Author

Antti Karttunen, Nov 15 2021

Keywords

Crossrefs

Programs

  • PARI
    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(dA001511(n) = 1+valuation(n,2);
    A003602(n) = (1+(n>>valuation(n,2)))/2;
    A181988(n) = (A001511(n)*A003602(n));
    v349346 = DirInverseCorrect(vector(up_to,n,A181988(n)));
    A349346(n) = v349346[n];

Formula

a(1) = 1; a(n) = -Sum_{d|n, d < n} A181988(n/d) * a(d).
a(n) = A349347(n) - A181988(n).

A349373 Dirichlet convolution of Kimberling's paraphrases (A003602) with Dirichlet inverse of Euler phi (A023900).

Original entry on oeis.org

1, 0, 0, -1, -1, 0, -2, -2, -1, 0, -4, 0, -5, 0, 2, -3, -7, 0, -8, 1, 3, 0, -10, 0, -3, 0, -2, 2, -13, 0, -14, -4, 5, 0, 8, 1, -17, 0, 6, 2, -19, 0, -20, 4, 5, 0, -22, 0, -5, 0, 8, 5, -25, 0, 14, 4, 9, 0, -28, -2, -29, 0, 8, -5, 17, 0, -32, 7, 11, 0, -34, 2, -35, 0, 4, 8, 23, 0, -38, 3, -3, 0, -40, -3, 23, 0, 14, 8
Offset: 1

Views

Author

Antti Karttunen, Nov 15 2021

Keywords

Crossrefs

Cf. A347954, A347955, A347956, A349136, A349370, A349371, A349372, A349374, A349375, A349390, A349431, A349444, A349447 for Dirichlet convolutions of other sequences with A003602.

Programs

  • Mathematica
    f[p_, e_] := (1 - p); d[1] = 1; d[n_] := Times @@ f @@@ FactorInteger[n]; k[n_] := (n / 2^IntegerExponent[n, 2] + 1)/2; a[n_] := DivisorSum[n, k[#] * d[n/#] &]; Array[a, 100] (* Amiram Eldar, Nov 16 2021 *)
  • PARI
    A003602(n) = (1+(n>>valuation(n,2)))/2;
    A023900(n) = factorback(apply(p -> 1-p, factor(n)[, 1]));
    A349373(n) = sumdiv(n,d,A003602(n/d)*A023900(d));

Formula

a(n) = Sum_{d|n} A003602(n/d) * A023900(d).

A351565 Odd part of Kimberling's paraphrases: a(n) = A000265(A003602(n)).

Original entry on oeis.org

1, 1, 1, 1, 3, 1, 1, 1, 5, 3, 3, 1, 7, 1, 1, 1, 9, 5, 5, 3, 11, 3, 3, 1, 13, 7, 7, 1, 15, 1, 1, 1, 17, 9, 9, 5, 19, 5, 5, 3, 21, 11, 11, 3, 23, 3, 3, 1, 25, 13, 13, 7, 27, 7, 7, 1, 29, 15, 15, 1, 31, 1, 1, 1, 33, 17, 17, 9, 35, 9, 9, 5, 37, 19, 19, 5, 39, 5, 5, 3, 41, 21, 21, 11, 43, 11, 11, 3, 45, 23, 23, 3, 47
Offset: 1

Views

Author

Antti Karttunen, Mar 27 2022

Keywords

Crossrefs

Cf. A000265, A003602, A023758 (gives the positions of 1's after its initial zero-term).
Cf. also A336698, A336699.

Programs

Formula

a(n) = A000265(A003602(n)) = A000265(1+A000265(n)).

A353366 Dirichlet inverse of A110963, which is a fractalization of Kimberling's paraphrases sequence (A003602).

Original entry on oeis.org

1, -1, -1, 0, -2, 1, -1, 0, -2, 2, -2, 0, -4, 1, 3, 0, -5, 2, -3, 0, -4, 2, -2, 0, -3, 4, 1, 0, -8, -3, -1, 0, -5, 5, -1, 0, -10, 3, 5, 0, -11, 4, -6, 0, -4, 2, -2, 0, -12, 3, 3, 0, -14, -1, 4, 0, -9, 8, -8, 0, -16, 1, 14, 0, -1, 5, -9, 0, -14, 1, -5, 0, -19, 10, -4, 0, -16, -5, -3, 0, -12, 11, -11, 0, -2, 6, 10
Offset: 1

Views

Author

Antti Karttunen, Apr 18 2022

Keywords

Crossrefs

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(dA003602(n) = (1+(n>>valuation(n,2)))/2;
    A110963(n) = if(n%2, A003602((1+n)/2), A110963(n/2));
    v353366 = DirInverseCorrect(vector(up_to,n,A110963(n)));
    A353366(n) = v353366[n];
    
  • Python
    from functools import lru_cache
    from sympy import divisors
    @lru_cache(maxsize=None)
    def A353366(n): return 1 if n==1 else -sum(((1+(m:=d>>(~d&d-1).bit_length())>>(m+1&-m-1).bit_length())+1)*A353366(n//d) for d in divisors(n,generator=True) if d>1) # Chai Wah Wu, Jan 04 2024

Formula

a(1) = 1; a(n) = -Sum_{d|n, d < n} A110963(n/d) * a(d).
a(n) = A353367(n) - A110963(n).

A304100 a(n) = A003602(A048679(n)).

Original entry on oeis.org

1, 1, 1, 2, 1, 3, 2, 1, 5, 3, 2, 4, 1, 9, 5, 3, 6, 2, 7, 4, 1, 17, 9, 5, 10, 3, 11, 6, 2, 13, 7, 4, 8, 1, 33, 17, 9, 18, 5, 19, 10, 3, 21, 11, 6, 12, 2, 25, 13, 7, 14, 4, 15, 8, 1, 65, 33, 17, 34, 9, 35, 18, 5, 37, 19, 10, 20, 3, 41, 21, 11, 22, 6, 23, 12, 2, 49, 25, 13, 26, 7, 27, 14, 4, 29, 15, 8, 16, 1, 129, 65, 33, 66, 17, 67, 34, 9, 69, 35, 18, 36, 5, 73
Offset: 1

Views

Author

Antti Karttunen, May 13 2018

Keywords

Comments

Positions of ones is given by the positive Fibonacci numbers: 1, 2, 3, 5, 8, 13, 21, ..., that is, A000045(n) from n >= 2 onward.
Positions of 2's is given by Lucas numbers larger than 3: 4, 7, 11, 18, ..., that is, A000032(n) from n >= 3 onward.
The restricted growth sequence transform of this sequence (almost certainly) is A003603.

Crossrefs

Programs

Formula

a(n) = A003602(A048679(n)).
For all i, j: a(i) = a(j) => A304101(i) = A304101(j).

A349137 a(n) = phi(A003602(n)), where A003602 is Kimberling's paraphrases, and phi is Euler totient function.

Original entry on oeis.org

1, 1, 1, 1, 2, 1, 2, 1, 4, 2, 2, 1, 6, 2, 4, 1, 6, 4, 4, 2, 10, 2, 4, 1, 12, 6, 6, 2, 8, 4, 8, 1, 16, 6, 6, 4, 18, 4, 8, 2, 12, 10, 10, 2, 22, 4, 8, 1, 20, 12, 12, 6, 18, 6, 12, 2, 28, 8, 8, 4, 30, 8, 16, 1, 20, 16, 16, 6, 24, 6, 12, 4, 36, 18, 18, 4, 24, 8, 16, 2, 40, 12, 12, 10, 42, 10, 20, 2, 24, 22, 22, 4, 46
Offset: 1

Views

Author

Antti Karttunen, Nov 13 2021

Keywords

Crossrefs

Cf. A000010, A000265, A003602, A349138 (inverse Möbius transform).
Cf. also A349136.

Programs

Formula

a(n) = A000010(A003602(n)).
For all n >= 1, a(n) = a(2*n) = a(A000265(n)), a(2n-1) = A000010(n).

A349138 Inverse Möbius transform of A349137, where A349137(n) = phi(A003602(n)).

Original entry on oeis.org

1, 2, 2, 3, 3, 4, 3, 4, 6, 6, 3, 6, 7, 6, 8, 5, 7, 12, 5, 9, 14, 6, 5, 8, 15, 14, 12, 9, 9, 16, 9, 6, 20, 14, 11, 18, 19, 10, 16, 12, 13, 28, 11, 9, 34, 10, 9, 10, 23, 30, 20, 21, 19, 24, 17, 12, 34, 18, 9, 24, 31, 18, 34, 7, 29, 40, 17, 21, 30, 22, 13, 24, 37, 38, 38, 15, 29, 32, 17, 15, 52, 26, 13, 42, 51, 22, 30
Offset: 1

Views

Author

Antti Karttunen, Nov 13 2021

Keywords

Crossrefs

Cf. also A349122.

Programs

Formula

a(n) = Sum_{d|n} A349137(d).
Previous Showing 21-30 of 154 results. Next