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 1-4 of 4 results.

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.

A356309 The least j >= n such that n and A276086(j) are relatively prime, where A276086 is the primorial base exp-function.

Original entry on oeis.org

0, 1, 2, 6, 4, 5, 6, 7, 8, 12, 30, 11, 12, 13, 14, 30, 16, 17, 18, 19, 30, 24, 22, 23, 24, 30, 26, 30, 28, 29, 30, 31, 32, 36, 34, 210, 36, 37, 38, 42, 60, 41, 210, 43, 44, 60, 46, 47, 48, 210, 60, 54, 52, 53, 54, 60, 210, 60, 58, 59, 60, 61, 62, 210, 64, 65, 66, 67, 68, 72, 210, 71, 72, 73, 74, 90, 76, 2310, 78
Offset: 0

Views

Author

Antti Karttunen, Nov 04 2022

Keywords

Crossrefs

Cf. A324583 (positions of the fixed points), A356314 (positions of the terms that are primorial numbers), A356316 (where a(n) is a multiple of n), A356318 (where a nontrivial multiple), A356319 (where n < a(n) < 2*n).

Programs

  • Mathematica
    f[nn_] := Block[{m = 1, i = 1, n = nn, p}, While[n > 0, p = Prime[i]; m *= p^Mod[n, p]; n = Quotient[n, p]; i++]; m]; Array[Block[{k = #}, While[! CoprimeQ[#, f[k]], k++]; k] &, 79, 0] (* Michael De Vlieger, Nov 06 2022, after Jean-François Alcover at A276086 *)
  • PARI
    A356309(n) = (n+A356302(n)); \\ See code in the latter sequence.

Formula

a(n) = n + A356302(n).

A356318 Numbers k such that the least j >= k for which k and A276086(j) are coprime is a nontrivial multiple of k, where A276086 is the primorial base exp-function.

Original entry on oeis.org

3, 10, 15, 35, 42, 70, 77, 105, 154, 231, 286, 330, 385, 429, 462, 715, 770, 858, 1001, 1155, 1430, 2002, 2145, 2431, 2730, 3003, 3094, 3315, 4199, 4290, 4641, 4862, 5005, 6006, 6630, 7293, 7735, 8398, 9282, 10010, 12155, 12597, 14586, 15015, 15470, 17017, 20995, 23205, 24310, 25194, 29393, 33915, 34034, 35530, 36465
Offset: 1

Views

Author

Antti Karttunen, Nov 04 2022

Keywords

Comments

Numbers k such that k divides A356309(k) and A356309(k) > k.
Numbers k for which A356302(k) is a nonzero multiple of k.

Crossrefs

Setwise difference A356316 \ A324583. Intersection of A324584 and A356316.

Programs

A356317 Numbers k such that k does not divide the least j >= k for which k and A276086(j) are coprime, where A276086 is the primorial base exp-function.

Original entry on oeis.org

9, 20, 21, 25, 27, 33, 39, 40, 45, 49, 50, 51, 55, 56, 57, 63, 69, 75, 80, 81, 84, 85, 87, 91, 93, 98, 99, 100, 110, 111, 112, 115, 117, 119, 123, 126, 129, 130, 133, 135, 140, 141, 145, 147, 153, 159, 160, 161, 165, 168, 170, 171, 175, 177, 182, 183, 189, 190, 195, 196, 200, 201, 203, 205, 207, 213, 219, 220, 225
Offset: 1

Views

Author

Antti Karttunen, Nov 04 2022

Keywords

Comments

Numbers k such that k does not divide A356309(k).

Crossrefs

Subsequence of A324584.
Positions of 0's in A356315.
Cf. A276086, A356309, A356316 (complement), A356319 (subsequence).

Programs

Showing 1-4 of 4 results.