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.

A075059 a(n) = 1 + lcm(1, 2, ..., n) = 1 + A003418(n).

Original entry on oeis.org

2, 2, 3, 7, 13, 61, 61, 421, 841, 2521, 2521, 27721, 27721, 360361, 360361, 360361, 720721, 12252241, 12252241, 232792561, 232792561, 232792561, 232792561, 5354228881, 5354228881, 26771144401, 26771144401, 80313433201, 80313433201
Offset: 0

Views

Author

Amarnath Murthy, Sep 08 2002

Keywords

Comments

Consider the triangle in which the n-th row contains the second run of n consecutive numbers such that the r-th term is divisible by r. Sequence gives the first column of the triangle. The first run trivially begins with 1.
Also the smallest of n consecutive integers (with the first greater than 1) divisible respectively by 1, 2, 3, ..., n. - Robert G. Wilson v, Oct 30 2014
Also the smallest number m > 1 such that m == 1 (mod i) for all 1 <= i <= n. - Franz Vrabec, Aug 18 2023

Examples

			First column of the triangle A075061:
   2;
   3,  4;
   7,  8,  9;
  13, 14, 15, 16;
  61, 62, 63, 64, 65;
  61, 62, 63, 64, 65, 66;
  ...
		

Crossrefs

Programs

Formula

a(n) = 1 + A003418(n).

Extensions

New definition from Vladeta Jovovic, Jun 16 2003
Edited by N. J. A. Sloane, Jul 01 2008 at the suggestion of R. J. Mathar
a(0)=2 prepended by Max Alekseyev, Sep 04 2015

A060401 a(n) = minimal m such that m>n, n divides m, n-1 divides m-1, n-2 divides m-2 and so on down to 1 divides m-n+1.

Original entry on oeis.org

2, 4, 9, 16, 65, 66, 427, 848, 2529, 2530, 27731, 27732, 360373, 360374, 360375, 720736, 12252257, 12252258, 232792579, 232792580, 232792581, 232792582, 5354228903, 5354228904, 26771144425, 26771144426, 80313433227, 80313433228, 2329089562829, 2329089562830
Offset: 1

Views

Author

Christopher Burrows (cburrows(AT)math.upenn.edu), Apr 04 2001

Keywords

Comments

A099427(a(n)) = n + 1. - Reinhard Zumkeller, Jul 02 2011

Examples

			a(5) = 65 because 5|65, 4|64, 3|63, 2|62, 1|61 and 65 is minimal.
		

Crossrefs

Rightmost diagonal of triangle in A075059. Cf. A075061, A075062.
Cf. A003418.

Programs

  • Maple
    seq(n+ilcm($1..n),n=1..100); # Robert Israel, Jul 19 2016

Formula

a(n) = n + lcm(seq(i, i=1..n)).
a(n) = n + A003418(n). - Robert Israel, Jul 19 2016

A075062 Row sums of triangle in A075059.

Original entry on oeis.org

2, 7, 24, 58, 315, 381, 2968, 6756, 22725, 25255, 304986, 332718, 4684771, 5045145, 5405520, 11531656, 208288233, 220540491, 4423058830, 4655851410, 4888643991, 5121436573, 123147264516, 128501493420, 669278610325, 696049754751
Offset: 1

Views

Author

Amarnath Murthy, Sep 08 2002

Keywords

Comments

For odd n, a(n) is a multiple of n.

Crossrefs

Formula

a(n)=n*A075059(n)+A000217(n-1). - R. J. Mathar, Mar 20 2007

Extensions

More terms from R. J. Mathar, Mar 20 2007
Showing 1-3 of 3 results.