A225628 a(n) = lcm(A225627(n),p1,p2,...,pk) for such a partition {p1+p2+...+pk} of n which maximizes this value among all partitions of n.

1, 1, 2, 6, 12, 60, 60, 420, 840, 1260, 840, 4620, 4620, 8580, 16380, 60060, 60060, 92820, 92820, 175560, 263340, 360360, 360360, 753480, 2762760, 6126120, 6126120, 8953560, 6846840, 13665960, 58198140, 58198140, 78738660, 78738660, 157477320, 157477320

Offset

0,3

Comments

Row 3 of A225630.

This could be called a "thrice-iterated Landau's function."

Links

Table of n, a(n) for n=0..35.

Index entries for sequences related to lcm's

Prog

(Scheme):
(define (A225628 n) (let ((maxlcm (list 0))) (fold_over_partitions_of n (A225627 n) lcm (lambda (p) (set-car! maxlcm (max (car maxlcm) p)))) (car maxlcm)))
;; Adapted by AK from Kreher & Stinson, CAGES-book, p. 68, Algorithm 3.1:
(define (fold_over_partitions_of m initval addpartfun colfun) (let recurse ((m m) (b m) (n 0) (partition initval)) (cond ((zero? m) (colfun partition)) (else (let loop ((i 1)) (recurse (- m i) i (+ 1 n) (addpartfun i partition)) (if (< i (min b m)) (loop (+ 1 i))))))))

Crossrefs

Cf. A225630, A225627, A225629.

Sequence in context: A341617 A083268 A368901 * A284650 A085911 A211418

Adjacent sequences: A225625 A225626 A225627 * A225629 A225630 A225631

Keyword

nonn

Author

Antti Karttunen, May 13 2013

Status

approved