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.

A159991 Powers of 60: a(n) = 60^n.

Original entry on oeis.org

1, 60, 3600, 216000, 12960000, 777600000, 46656000000, 2799360000000, 167961600000000, 10077696000000000, 604661760000000000, 36279705600000000000, 2176782336000000000000, 130606940160000000000000, 7836416409600000000000000, 470184984576000000000000000
Offset: 0

Views

Author

Reinhard Zumkeller, May 01 2009

Keywords

Examples

			G.f. = 1 + 60*x + 3600*x^2 + 216000*x^3 + 12960000*x^4 + 77600000*x^5 + ... - _Michael Somos_, Jan 01 2019
		

Crossrefs

Programs

Formula

a(n) = A000400(n)*A011557(n) = A000351(n)*A001021(n) = A000302(n)*A001024(n) = A000244(n)*A009964(n). (Corrected by Robert B Fowler, Jan 25 2023)
From Muniru A Asiru, Nov 21 2018: (Start)
a(n) = 60^n.
a(n) = 60*a(n-1) for n > 0, a(0) = 1.
G.f.: 1/(1-60*x).
E.g.f: exp(60*x). (End)
a(n) = 1/a(-n) for all n in Z. - Michael Somos, Jan 01 2019

A100826 a(1) = 1; a(n+1) = gcd(n,a(n))-th smallest positive integer not already in the sequence.

Original entry on oeis.org

1, 2, 4, 3, 5, 10, 7, 14, 8, 6, 11, 22, 12, 9, 13, 15, 16, 17, 18, 19, 20, 21, 23, 46, 25, 50, 26, 24, 30, 27, 31, 62, 29, 28, 33, 32, 37, 74, 35, 34, 38, 36, 44, 39, 40, 47, 41, 42, 52, 43, 45, 51, 48, 49, 53, 54, 56, 55, 57, 58, 60, 59, 61, 63, 64, 65, 66, 67, 68, 69, 70, 71
Offset: 1

Views

Author

Leroy Quet, Jan 06 2005

Keywords

Comments

Probably a permutation of the positive integers.
This is a permutation iff, infinitely often, gcd(n, a(n)) = 1. Through n = 1000, gcd(n, a(n)) = 1 612 times, which is consistent with the natural conjecture that this is true with density 6/Pi^2 ~ 0.6079.... - Franklin T. Adams-Watters, Nov 28 2006

Crossrefs

Cf. A125628.

Programs

  • Mathematica
    a[1] = 1; a[n_] := a[n] = Complement[ Range[250], Table[a[i], {i, n - 1}]][[GCD[n - 1, a[n - 1]]]]; Table[ a[n], {n, 60}] (* Robert G. Wilson v, Jan 10 2005 *)

Extensions

More terms from Robert G. Wilson v, Jan 10 2005
Showing 1-2 of 2 results.