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.

A246692 Numbers k such that k | A000129(k).

This page as a plain text file.
%I A246692 #20 Mar 31 2021 03:54:14
%S A246692 1,2,4,8,12,16,24,32,36,48,60,64,72,84,96,108,120,128,132,136,144,168,
%T A246692 180,192,216,240,252,256,264,272,288,300,324,336,360,384,396,408,420,
%U A246692 432,480,504,512,528,540,544,576,588,600,648,660,672,720,756,768
%N A246692 Numbers k such that k | A000129(k).
%C A246692 These are the numbers k such that mean of the k-th row of the Delannoy triangle at A027926 is an integer.  All such k except 0 and 1 are multiples of 4.
%C A246692 Is A181824 a subsequence? The first 31 terms appear in this sequence. - _Jaycob Coleman_, Mar 08 2015 [The first 323 terms of A181824 appear in this sequence. - _Amiram Eldar_, Mar 31 2021]
%H A246692 Amiram Eldar, <a href="/A246692/b246692.txt">Table of n, a(n) for n = 1..10000</a>
%e A246692 Row 4 of the Delannoy triangle is (1,5,5,1), with sum 12 = A000129(4) divisible by 4.
%t A246692 z = 1000; t = LinearRecurrence[{2, 1}, {1, 2}, z]; (* A000129 *)
%t A246692 Select[Range[1, z], IntegerQ[t[[#]]/#] &]   (* A246692 *)
%t A246692 Table[t[[u[[n]]]]/u[[n]], {n, 1, 17}]  (* A246693 *)
%Y A246692 Cf. A246693, A000129, A027926.
%Y A246692 Cf. A181824.
%K A246692 nonn,easy
%O A246692 1,2
%A A246692 _Clark Kimberling_, Sep 01 2014