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.

A369685 Least common multiple of the first n terms of A359804.

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%I A369685 #13 Feb 03 2024 10:12:21
%S A369685 1,1,2,6,30,60,60,60,420,1260,2520,2520,2520,27720,27720,27720,27720,
%T A369685 27720,138600,138600,138600,138600,138600,138600,277200,277200,277200,
%U A369685 277200,277200,277200,1940400,25225200,75675600,75675600,75675600,75675600,75675600,75675600
%N A369685 Least common multiple of the first n terms of A359804.
%H A369685 Michael De Vlieger, <a href="/A369685/b369685.txt">Table of n, a(n) for n = 0..6187</a>
%F A369685 a(0) = 1, and for n >0, a(n) = lcm(A359804(n), a(n-1)).
%t A369685 nn = 40; c[_] = False; q[_] = 1;
%t A369685 Array[Set[{a[#], c[#]}, {1, True}] &, 2];
%t A369685 Set[{i, j}, {1, 2}]; m = 2; u = 3;
%t A369685 Do[
%t A369685   (k = q[#]; While[c[k #], k++]; k *= #; While[c[# q[#]], q[#]++]) &[
%t A369685   (p = 2; While[Divisible[i j, p], p = NextPrime[p]]; p)];
%t A369685   Set[{a[n], c[k], i, j, m}, {m, True, j, k, #}] &[LCM[m, k]];
%t A369685   If[k == u, While[c[u], u++]], {n, 3, nn}];
%t A369685 Array[a, nn] (* _Michael De Vlieger_, Jan 29 2024 *)
%Y A369685 Cf. A003418, A359804, A368901, A369686.
%K A369685 nonn
%O A369685 0,3
%A A369685 _David James Sycamore_, Jan 28 2024