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 1-3 of 3 results.

A324583 Numbers k such that k and A276086(k) are coprime, where A276086 is the primorial base exp-function.

Original entry on oeis.org

0, 1, 2, 4, 5, 6, 7, 8, 11, 12, 13, 14, 16, 17, 18, 19, 22, 23, 24, 26, 28, 29, 30, 31, 32, 34, 36, 37, 38, 41, 43, 44, 46, 47, 48, 52, 53, 54, 58, 59, 60, 61, 62, 64, 65, 66, 67, 68, 71, 72, 73, 74, 76, 78, 79, 82, 83, 86, 88, 89, 90, 92, 94, 95, 96, 97, 101, 102, 103, 104, 106, 107, 108, 109, 113, 114, 116, 118, 120, 121
Offset: 1

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Author

Antti Karttunen, Mar 10 2019

Keywords

Comments

Numbers k for which A324198(k) = 1.
For terms k > 0 it holds that:
A000005(A324580(k)) = A000005(k) * A324655(k),
A000010(A324580(k)) = A000010(k) * A324650(k),
A000203(A324580(k)) = A000203(k) * A324653(k),
and similarly for any multiplicative function.

Crossrefs

Cf. A324584 (complement), A356162 (characteristic function).
Some subsequences are: A055932A025487A002182, and also A002110.
Subsequence of A356316.
Positions of 1's in A324198, positions 0's in A351254, A356302 and A356303, positions of fixed points in A351250 and in A356309.
Cf. also A355821, A356311.

Programs

  • PARI
    A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
    A324198(n) = gcd(n,A276086(n));
    for(n=0,oo,if(1==A324198(n),print1(n,", ")));

Extensions

Initial 0 prepended by Antti Karttunen, Nov 03 2022

A356302 The least k >= 0 such that n and A276086(n+k) are relatively prime, where A276086 is the primorial base exp-function.

Original entry on oeis.org

0, 0, 0, 3, 0, 0, 0, 0, 0, 3, 20, 0, 0, 0, 0, 15, 0, 0, 0, 0, 10, 3, 0, 0, 0, 5, 0, 3, 0, 0, 0, 0, 0, 3, 0, 175, 0, 0, 0, 3, 20, 0, 168, 0, 0, 15, 0, 0, 0, 161, 10, 3, 0, 0, 0, 5, 154, 3, 0, 0, 0, 0, 0, 147, 0, 0, 0, 0, 0, 3, 140, 0, 0, 0, 0, 15, 0, 2233, 0, 0, 10, 3, 0, 0, 126, 5, 0, 3, 0, 0, 0, 119, 0, 3, 0, 0, 0, 0, 112
Offset: 0

Views

Author

Antti Karttunen, Nov 03 2022

Keywords

Comments

For all nonzero terms, adding a(n) to n in primorial base generates at least one carry. See the formula involving A329041.

Crossrefs

Cf. A324583 (positions of zeros), A324584 (of nonzeros), A356318 (positions where a(n) > 0 and a multiple of n), A356319 (where 0 < a(n) < n).
Cf. A358213, A358214 (conjectured positions of records and their values).
Cf. also A356303, A356304.

Programs

  • PARI
    A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
    A356302(n) = { my(k=0); while(gcd(A276086(n+k),n)!=1,k++); (k); };

Formula

a(n) = A356309(n) - n.
If a(n) > 0, then A000035(a(n)) = A000035(n) and A329041(n, a(n)) > 1.

A356305 The least k >= 0 such that A003415(n) and A276086(n-k) are relatively prime, where A003415 is the arithmetic derivative, and A276086 is the primorial base exp-function.

Original entry on oeis.org

0, 1, 0, 0, 0, 0, 1, 0, 2, 3, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 2, 17, 0, 0, 0, 21, 25, 2, 0, 0, 0, 0, 0, 5, 0, 5, 6, 0, 13, 1, 0, 0, 0, 0, 2, 2, 11, 0, 20, 21, 19, 17, 24, 0, 0, 1, 0, 1, 0, 0, 0, 0, 1, 2, 4, 5, 0, 0, 2, 1, 0, 0, 0, 0, 1, 10, 12, 5, 0, 0, 0, 3, 0, 0, 0, 1, 25, 1, 84, 0, 0, 1, 2, 1, 65, 5, 0, 0, 69, 8, 96
Offset: 0

Views

Author

Antti Karttunen, Nov 03 2022

Keywords

Crossrefs

Cf. A003415, A276086, A356311 (positions of 0's).
Cf. also A356303, A356304.

Programs

  • PARI
    A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
    A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
    A356305(n) = { my(k=0,x=A003415(n)); while(gcd(A276086(n-k),x)!=1,k++); (k); };
Showing 1-3 of 3 results.