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 1-2 of 2 results.

A363457 Positions of products of distinct primorial numbers (A129912) in the sequence of products of primorial numbers (A025487).

Original entry on oeis.org

1, 2, 4, 6, 9, 13, 20, 22, 27, 29, 43, 54, 55, 66, 72, 89, 93, 112, 114, 123, 140, 147, 150, 175, 186, 223, 232, 242, 246, 274, 279, 285, 290, 332, 371, 376, 425, 433, 439, 442, 488, 500, 518, 535, 539, 570, 619, 624, 656, 718, 747, 761, 783, 789, 816, 831, 860
Offset: 1

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Author

Amiram Eldar, Jun 03 2023

Keywords

Comments

Numbers k such that A025487(k) is a term of A129912.
Numbers k such that A051282(k) = A363455(k).
What is the asymptotic behavior of this sequence? Empirically, it seems that a(n) ~ A * n^c, where A and c are constants.

Crossrefs

Programs

  • Mathematica
    lps = Cases[Import["https://oeis.org/A025487/b025487.txt", "Table"], {, }][[;; , 2]];
    prod = Cases[Import["https://oeis.org/A129912/b129912.txt", "Table"], {, }][[;; , 2]];
    Position[lps, #] & /@ prod // Flatten

Formula

A025487(a(n)) = A129912(n).

A363456 Positions of the terms of the Chernoff sequence (A006939) in A025487.

Original entry on oeis.org

1, 2, 6, 27, 150, 900, 5697, 37226, 246280, 1648592, 11204274
Offset: 0

Views

Author

Amiram Eldar, Jun 03 2023

Keywords

Comments

Indices of records in A363455.

Examples

			A006939(0) = A025487(1) = 1, so a(0) = 1.
A006939(1) = A025487(2) = 2, so a(1) = 2.
A006939(2) = A025487(6) = 12, so a(2) = 6.
		

Crossrefs

Programs

  • Mathematica
    lps = Cases[Import["https://oeis.org/A025487/b025487.txt", "Table"], {, }][[;; , 2]];
    cher = Table[Product[Prime[k]^(n - k + 1), {k, 1, n}], {n, 0, 8}]
    Position[lps, #] & /@ cher // Flatten

Formula

A025487(a(n)) = A006939(n).
A363455(a(n)) = n.
Showing 1-2 of 2 results.