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.

A105069 Number of distinct prime divisors of 100^n - 3.

Original entry on oeis.org

1, 2, 2, 2, 2, 2, 2, 4, 4, 4, 2, 2, 3, 3, 3, 4, 2, 4, 3, 5, 5, 4, 4, 5, 4, 4, 2, 4, 5, 4, 3, 4, 3, 5, 5, 3, 5, 5, 4, 4, 5, 5, 2, 3, 6, 4, 4, 8, 4, 4, 6, 3, 4, 6, 6, 5, 6, 5, 5, 3, 3, 7, 8, 5, 5, 3, 3, 5, 4, 1, 6, 4, 5, 6, 3, 5, 6, 6, 4, 5, 7, 3, 3, 7, 3, 6, 4, 5, 6, 8, 2, 7, 3, 4, 8, 6, 6, 7, 5, 4, 8, 6, 6, 5, 4, 4, 6, 4, 3, 5, 7
Offset: 1

Views

Author

Parthasarathy Nambi, Apr 05 2005

Keywords

Examples

			If n = 1, then 100^1 - 3 = 97 which is prime so the first term is 1.
		

Crossrefs

Programs

  • Maple
    A105069 := proc(n) 100^n-3 ; numtheory[factorset](%) ; nops(%) ; end proc: # R. J. Mathar, Aug 24 2011
  • Mathematica
    Table[PrimeNu[(100)^n - 3], {n, 1, 50}] (* G. C. Greubel, May 07 2017 *)

Formula

a(n) = A001221(100^n-3).
a(n) = A105068(2*n). - Amiram Eldar, Jan 25 2020

Extensions

a(31)-a(60) from Amiram Eldar, Jan 25 2020
a(61)-a(66) from Jinyuan Wang, Apr 01 2020
a(67)-a(111) from Michael S. Branicky, Apr 14 2023 using factorbd.com

A105080 Number of distinct prime divisors of 10000^n - 3.

Original entry on oeis.org

2, 2, 2, 4, 4, 2, 3, 4, 4, 5, 4, 5, 4, 4, 4, 4, 5, 3, 5, 4, 5, 3, 4, 8, 4, 3, 6, 5, 5, 3, 7, 5, 3, 5, 1, 4, 6, 5
Offset: 1

Views

Author

Parthasarathy Nambi, Apr 06 2005

Keywords

Examples

			The number of distinct prime divisors of 10000^1 - 3 is 2, so the first term is 2.
		

Crossrefs

Programs

  • Mathematica
    PrimeNu[#]&/@(10000^Range[10]-3) (* The program generates the first 10 terms of the sequence. *) (* Harvey P. Dale, Feb 05 2023 *)

Formula

A105080(n) = A105068(4n) = A105069(2n). - Robert G. Wilson v, Apr 08 2005

Extensions

More terms from Robert G. Wilson v, Apr 08 2005

A105079 Number of distinct prime divisors of 1000^n - 3 where n = 1,2,3,....

Original entry on oeis.org

1, 2, 3, 2, 4, 4, 2, 2, 4, 3, 3, 4, 5, 5, 5, 5, 5, 2, 2, 4, 3, 3, 6, 3, 6, 4, 3, 5, 6, 6, 5, 8, 5, 6, 3, 6, 4, 6, 2, 3, 5, 8, 3, 3, 2, 4, 5, 4, 5, 3, 6, 6, 5, 7, 4, 7, 4, 4, 2, 8
Offset: 1

Views

Author

Parthasarathy Nambi, Apr 06 2005

Keywords

Examples

			If n=1, then 1000^n - 3 = 1000^1 - 3 = 997 which is a prime, so the first term is 1.
		

Crossrefs

Showing 1-3 of 3 results.