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

Author

Antti Karttunen, May 24 2013

Keywords

• nonn

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.

Examples

			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.
		

Links

• Index entries for sequences related to lcm's

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.

Programs

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.

Formula

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