login
A225627
a(n) = lcm(A000793(n),p1,p2,...,pk) for such a partition {p1+p2+...+pk} of n that maximizes this value among all partitions of n.
4
1, 1, 2, 6, 12, 30, 30, 84, 120, 180, 210, 420, 660, 780, 1260, 4620, 5460, 5460, 5460, 9240, 13860, 13860, 16380, 32760, 120120, 180180, 180180, 235620, 180180, 471240, 1021020, 1021020, 1141140, 1141140, 2282280, 2282280, 4476780, 4476780, 6846840, 6846840
OFFSET
0,3
COMMENTS
Row 2 of A225630.
This could be called a "twice-iterated Landau's function."
FORMULA
a(n) = A225636(n)*A000793(n).
PROG
(Scheme):
(define (A225627 n) (let ((maxlcm (list 0))) (fold_over_partitions_of n (A000793 n) lcm (lambda (p) (set-car! maxlcm (max (car maxlcm) p)))) (car maxlcm)))
(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
KEYWORD
nonn
AUTHOR
Antti Karttunen, May 13 2013
STATUS
approved