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.

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A126357 a(n) is the (n+1)st integer from among the positive integers which are coprime to n.

Original entry on oeis.org

2, 5, 5, 9, 7, 19, 9, 17, 14, 27, 13, 37, 15, 33, 29, 33, 19, 55, 21, 51, 38, 49, 25, 73, 32, 57, 41, 67, 31, 113, 33, 65, 56, 73, 52, 109, 39, 81, 64, 101, 43, 149, 45, 97, 86, 97, 49, 145, 58, 127, 82, 113, 55, 163, 76, 131, 91, 121, 61, 227, 63, 129, 110, 129, 88, 221, 69
Offset: 1

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Author

Leroy Quet, Dec 26 2006

Keywords

Examples

			The positive integers which are coprime to 6 are 1,5,7,11,13,17,19,23,... The 7th of these is 19, which is a(6).
		

Crossrefs

Programs

  • Mathematica
    f[n_] := Block[{k = 0, c = n + 1},While[c > 0,k++;While[GCD[k, n] > 1, k++ ];c--;];k];Table[f[n], {n, 67}] (* Ray Chandler, Dec 29 2006 *)

Extensions

Extended by Ray Chandler, Dec 29 2006

A139766 A number n is included in the sequence if and only if the n-th integer from among those positive integers which are coprime to n+1 = the (n+1)-st integer from among those positive integers which are coprime to n.

Original entry on oeis.org

3, 15, 104, 164, 255, 2625, 2834, 11715, 18315, 48704, 49215, 64004, 65535, 73124, 131144, 215775, 491535, 525986, 546272, 568815, 952575, 1925564, 5781434, 5861583, 13496384, 14409548, 17646615, 17949434, 20171384, 21475124, 22632285
Offset: 1

Views

Author

Leroy Quet, Nov 07 2007

Keywords

Comments

So far it appears that this is a proper subset of A001274.

Crossrefs

Formula

Indices n such that A126356(n) = A126357(n). - Ray Chandler

Extensions

More terms from Stefan Steinerberger, Nov 07 2007
a(8) onwards from Ray Chandler, Jul 01 2009
Showing 1-2 of 2 results.