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 1-8 of 8 results.

A346470 a(n) = psi(A276086(n)), where psi is Dedekind psi function A001615, and A276086 is the prime product form of primorial base expansion of n.

Original entry on oeis.org

1, 3, 4, 12, 12, 36, 6, 18, 24, 72, 72, 216, 30, 90, 120, 360, 360, 1080, 150, 450, 600, 1800, 1800, 5400, 750, 2250, 3000, 9000, 9000, 27000, 8, 24, 32, 96, 96, 288, 48, 144, 192, 576, 576, 1728, 240, 720, 960, 2880, 2880, 8640, 1200, 3600, 4800, 14400, 14400, 43200, 6000, 18000, 24000, 72000, 72000, 216000, 56, 168, 224, 672
Offset: 0

Views

Author

Antti Karttunen, Jul 21 2021

Keywords

Crossrefs

Cf. A001615.
Other number-theoretical functions similarly applied to A276086: A267263 (omega), A276150 (bigomega), A324650 (phi), A324653 (sigma), A324655 (tau), A327860 (arithmetic derivative).
Cf. also A346471, A346475.

Programs

  • PARI
    A346470(n) = { my(m=1, p=2, e); while(n, e = (n%p); if(e, m *= (p+1)*(p^(e-1))); n = n\p; p = nextprime(1+p)); (m); };

Formula

a(n) = A001615(A276086(n)).

A347126 a(n) = A347129(A276086(n)).

Original entry on oeis.org

0, 1, 1, 10, 3, 21, 1, 14, 16, 124, 39, 246, 3, 27, 33, 222, 72, 423, 6, 44, 56, 344, 114, 636, 10, 65, 85, 490, 165, 885, 1, 18, 20, 164, 51, 330, 24, 236, 284, 1976, 636, 3804, 57, 438, 552, 3468, 1143, 6462, 104, 696, 904, 5296, 1776, 9624, 165, 1010, 1340, 7460, 2535, 13290, 3, 33, 39, 282, 90, 549, 51, 414, 516
Offset: 0

Views

Author

Antti Karttunen, Aug 25 2021

Keywords

Crossrefs

Programs

Formula

a(n) = A347129(A276086(n)).

A347396 a(n) = A347395(A276086(n)), where A347395 is Dirichlet convolution of Liouville's lambda with A342001.

Original entry on oeis.org

0, 1, 1, 3, 1, 2, 1, 5, 6, 14, 5, 9, 1, 2, 3, 5, 2, 3, 2, 6, 8, 16, 6, 10, 2, 3, 5, 7, 3, 4, 1, 7, 8, 20, 7, 13, 10, 34, 44, 92, 34, 58, 7, 13, 20, 32, 13, 19, 16, 40, 56, 104, 40, 64, 13, 19, 32, 44, 19, 25, 1, 2, 3, 5, 2, 3, 5, 9, 14, 22, 9, 13, 2, 3, 5, 7, 3, 4, 6, 10, 16, 24, 10, 14, 3, 4, 7, 9, 4, 5, 2, 8, 10, 22
Offset: 0

Views

Author

Antti Karttunen, Sep 02 2021

Keywords

Comments

The scatter plot looks quite peculiar. - Antti Karttunen, Sep 20 2021

Crossrefs

Programs

A346475 a(n) = A342919(A276086(n)).

Original entry on oeis.org

0, 1, 1, 5, 1, 7, 1, 7, 1, 31, 13, 41, 1, 1, 11, 37, 2, 47, 1, 11, 7, 43, 19, 53, 2, 13, 17, 49, 11, 59, 1, 3, 5, 41, 17, 55, 1, 59, 71, 247, 53, 317, 19, 73, 23, 289, 127, 359, 13, 29, 113, 331, 37, 401, 11, 101, 67, 373, 169, 443, 1, 11, 13, 47, 5, 61, 17, 23, 43, 277, 121, 347, 1, 83, 107, 319, 71, 389, 31, 97, 2, 361, 163
Offset: 0

Views

Author

Antti Karttunen, Jul 21 2021

Keywords

Comments

For n >= 1, each term a(n) is a divisor of A342002(n).

Crossrefs

Cf. also A342002, A345930, A346474 for sequences with similar scatter plots.

Programs

  • PARI
    A001615(n) = if(1==n,n, my(f=factor(n)); prod(i=1, #f~, f[i, 1]^f[i, 2] + f[i, 1]^(f[i, 2]-1))); \\ After code in A001615
    A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
    A342919(n) = { my(u=A003415(n)); (u/gcd(u, A001615(n))); };
    A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
    A346475(n) = A342919(A276086(n));

Formula

a(n) = A342919(A276086(n)).
a(n) = A327860(n) / gcd(A327860(n), A346470(n)).

A347232 a(n) = A346485(A276086(n)), where A346485 is Möbius transform of A342001.

Original entry on oeis.org

0, 1, 1, 3, 1, 1, 1, 5, 6, 14, 4, 4, 1, 1, 2, 2, 0, 0, 1, 1, 2, 2, 0, 0, 1, 1, 2, 2, 0, 0, 1, 7, 8, 20, 6, 6, 10, 34, 44, 92, 24, 24, 6, 6, 12, 12, 0, 0, 6, 6, 12, 12, 0, 0, 6, 6, 12, 12, 0, 0, 1, 1, 2, 2, 0, 0, 4, 4, 8, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 2, 2, 0, 0, 4, 4, 8, 8
Offset: 0

Views

Author

Antti Karttunen, Aug 26 2021

Keywords

Crossrefs

Programs

Formula

a(n) = A346485(A276086(n)).

A348997 a(n) = A348733(A276086(n)), where A348733(n) = gcd(A003959(n), A034448(n)), and A276086 gives the prime product form of primorial base expansion of n.

Original entry on oeis.org

1, 3, 4, 12, 2, 6, 6, 18, 24, 72, 12, 36, 2, 6, 8, 24, 4, 12, 18, 54, 72, 216, 36, 108, 2, 6, 8, 24, 4, 12, 8, 24, 32, 96, 16, 48, 48, 144, 192, 576, 96, 288, 16, 48, 64, 192, 32, 96, 144, 432, 576, 1728, 288, 864, 16, 48, 64, 192, 32, 96, 2, 6, 8, 24, 4, 12, 12, 36, 48, 144, 24, 72, 4, 12, 16, 48, 8, 24, 36, 108, 144
Offset: 0

Views

Author

Antti Karttunen, Nov 07 2021

Keywords

Crossrefs

Cf. also A346471 for similar construction. (Compare the scatter plots).

Programs

  • PARI
    A348997(n) = { my(m1=1, m2=1, p=2); while(n, if(n%p, m1 *= ((1+p)^(n%p)); m2 *= (1+(p^(n%p)))); n = n\p; p = nextprime(1+p)); gcd(m1, m2); };

Formula

a(n) = A348733(A276086(n)) = gcd(A348949(n), A348996(n)).

A346469 a(n) = A340070(A276086(n)).

Original entry on oeis.org

0, 1, 1, 5, 3, 3, 1, 7, 8, 31, 3, 3, 5, 5, 5, 5, 120, 15, 25, 25, 50, 25, 75, 75, 125, 125, 125, 125, 750, 375, 1, 9, 10, 41, 3, 3, 12, 59, 71, 247, 3, 3, 5, 5, 5, 5, 15, 15, 50, 25, 25, 25, 75, 75, 375, 125, 125, 125, 375, 375, 7, 7, 7, 7, 210, 21, 7, 7, 7, 7, 21, 21, 420, 35, 35, 35, 7455, 105, 175, 175, 175, 3325
Offset: 0

Views

Author

Antti Karttunen, Jul 21 2021

Keywords

Crossrefs

Programs

  • PARI
    A346469(n) = { my(s=0, t=0, m=1, p=2, e); while(n, e = (n%p); if(e, m *= (p^e); s += (1/p); t += (e/p)); n = n\p; p = nextprime(1+p)); (gcd(s,t)*m); };

Formula

a(n) = A340070(A276086(n)) = gcd(A327860(n), A329029(n)).
For n >= 1, a(n) = A327860(n) / A345930(n).

A366795 a(n) = A344695(A005940(1+n)), where A344695(n) = gcd(psi(n), sigma(n)), and A005940 is the Doudna sequence.

Original entry on oeis.org

1, 3, 4, 1, 6, 12, 1, 3, 8, 18, 24, 4, 1, 3, 4, 1, 12, 24, 32, 6, 48, 72, 6, 12, 1, 3, 4, 1, 6, 12, 1, 3, 14, 36, 48, 8, 72, 96, 8, 18, 96, 144, 192, 24, 8, 18, 24, 4, 1, 3, 4, 1, 6, 12, 1, 3, 8, 18, 24, 8, 1, 3, 4, 1, 18, 42, 56, 12, 84, 144, 12, 24, 112, 216, 288, 32, 12, 24, 32, 6, 168, 288, 384, 48, 576, 576
Offset: 0

Views

Author

Antti Karttunen, Oct 26 2023

Keywords

Crossrefs

Cf. A005940, A344695, A366796 (rgs-transform).
Cf. also A346471, A366801, A366803.

Programs

  • PARI
    A001615(n) = if(1==n,n, my(f=factor(n)); prod(i=1, #f~, f[i, 1]^f[i, 2] + f[i, 1]^(f[i, 2]-1))); \\ After code in A001615
    A005940(n) = { my(p=2, t=1); n--; until(!n\=2, if((n%2), (t*=p), p=nextprime(p+1))); (t); };
    A344695(n) = gcd(sigma(n), A001615(n));
    A366795(n) = A344695(A005940(1+n));
Showing 1-8 of 8 results.