A226055 a(n) is the first common term in column n of tables A225630 and A225640, when scanned from the top to bottom.

1, 1, 2, 3, 4, 30, 6, 84, 120, 180, 210, 4620, 4620, 780, 360360, 360360, 240240, 92820, 12252240, 175560, 58198140, 116396280, 360360, 753480, 2677114440, 13385572200, 26771144400, 40156716600, 2677114440, 13665960, 2329089562800, 82990547640, 48134517631200

Offset

0,3

Comments

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.

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.

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.

Links

Table of n, a(n) for n=0..32.

Index entries for sequences related to lcm's

Formula

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

Example

Row 8 of A225632 is 1, 15, 120, 840;
Row 8 of A225642 is 8, 120, 840;
Their first common term from the left is 120, thus a(8)=120.

Prog

(Scheme):
(define (A226055 n) (A225630bi n (A225638 n)))
(define (A226055 n) (A225640bi n (A225639 n))) ;; Alternative definition.
;; The Scheme-definitions of A225630bi and A225640bi given respectively in A225630 and A225640.

Crossrefs

Cf. A225630, A225640, A225638, A225639.

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

Sequence in context: A059614 A333074 A241974 * A028426 A024633 A326829

Adjacent sequences: A226052 A226053 A226054 * A226056 A226057 A226058

Keyword

nonn

Author

Antti Karttunen, May 24 2013

Status

approved