A226055 - OEIS

%I #15 Mar 13 2018 04:08:14

%S 1,1,2,3,4,30,6,84,120,180,210,4620,4620,780,360360,360360,240240,

%T 92820,12252240,175560,58198140,116396280,360360,753480,2677114440,

%U 13385572200,26771144400,40156716600,2677114440,13665960,2329089562800,82990547640,48134517631200

%N a(n) is the first common term in column n of tables A225630 and A225640, when scanned from the top to bottom.

%C Consider an algorithm which finds a maximum value lcm(p1,p2,...,pk,prevmax) among all partitions {p1+p2+...+pk} of n, where the "seed number" prevmax is such a maximum value from the previous iteration.

%C a(n) gives the first identical value encountered, after repeated iterations, when starting from the initial seed value 1, and when starting from the initial seed value of n.

%C Equivalently, the first common term occurring on the row n of tables A225632 and A225642, when scanning the rows from the left. These are A225638(n)-th and A225639(n)-th terms from the beginning of each row, respectively.

%H <a href="/index/Lc#lcm">Index entries for sequences related to lcm's</a>

%F a(n) = A225630(A225638(n),n) = A225640(A225639(n),n).

%e Row 8 of A225632 is 1, 15, 120, 840;

%e Row 8 of A225642 is 8, 120, 840;

%e Their first common term from the left is 120, thus a(8)=120.

%o (Scheme):

%o (define (A226055 n) (A225630bi n (A225638 n)))

%o (define (A226055 n) (A225640bi n (A225639 n))) ;; Alternative definition.

%o ;; The Scheme-definitions of A225630bi and A225640bi given respectively in A225630 and A225640.

%Y Cf. A225630, A225640, A225638, A225639.

%Y Also, a(n) is the A226056(n)-th rightmost term on the row n in tables A225632 and A225642.

%K nonn

%O 0,3

%A _Antti Karttunen_, May 24 2013