OFFSET
1,2
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..2011 (terms 1..80 from Reinhard Zumkeller)
EXAMPLE
. n | x = A260633(n) | y = a(n) | [x/y] | x mod y
. ----+-----------------------+----------------------+-------+---------
. 1 | 1 | 1 | 1 | 1 | 1 | 0
. 2 | 6 | 2*3 | 2 | 2 | 3 | 0
. 3 | 12 | 2^2*3 | 3 | 3 | 4 | 0
. 4 | 24 | 2^3*3 | 4 | 2^2 | 6 | 0
. 5 | 30 | 2*3*5 | 6 | 2*3 | 5 | 0
. 6 | 60 | 2^2*3*5 | 12 | 2^2*3 | 5 | 0
. 7 | 120 | 2^3*3*5 | 20 | 2^2*5 | 6 | 0
. 8 | 180 | 2^2*3^2*5 | 30 | 2*3*5 | 6 | 0
. 9 | 360 | 2^3*3^2*5 | 60 | 2^2*3*5 | 6 | 0
. 10 | 720 | 2^4*3^2*5 | 105 | 3*5*7 | 6 | 90
. 11 | 840 | 2^3*3*5*7 | 120 | 2^3*3*5 | 7 | 0
. 12 | 1080 | 2^3*3^3*5 | 140 | 2^2*5*7 | 7 | 100
. 13 | 1260 | 2^2*3^2*5*7 | 180 | 2^2*3^2*5 | 7 | 0
. 14 | 1680 | 2^4*3*5*7 | 210 | 2*3*5*7 | 8 | 0
. 15 | 2160 | 2^4*3^3*5 | 280 | 2^3*5*7 | 7 | 200
. 16 | 2520 | 2^3*3^2*5*7 | 420 | 2^2*3*5*7 | 6 | 0
. 17 | 4320 | 2^5*3^3*5 | 504 | 2^3*3^2*7 | 8 | 288
. 18 | 5040 | 2^4*3^2*5*7 | 840 | 2^3*3*5*7 | 6 | 0
. 19 | 7560 | 2^3*3^3*5*7 | 1120 | 2^5*5*7 | 6 | 840
. 20 | 10080 | 2^5*3^2*5*7 | 1512 | 2^3*3^3*7 | 6 | 1008
. 21 | 12600 | 2^3*3^2*5^2*7 | 1680 | 2^4*3*5*7 | 7 | 840
. 22 | 15120 | 2^4*3^3*5*7 | 2520 | 2^3*3^2*5*7 | 6 | 0
. 23 | 25200 | 2^4*3^2*5^2*7 | 3780 | 2^2*3^3*5*7 | 6 | 2520
. 24 | 30240 | 2^5*3^3*5*7 | 5040 | 2^4*3^2*5*7 | 6 | 0
. 25 | 45360 | 2^4*3^4*5*7 | 6300 | 2^2*3^2*5^2*7 | 7 | 1260 .
PROG
(Haskell)
a260987 n = a260987_list !! (n-1)
(a260987_list, a260633_list) = unzip $ f 1 0 where
f x r = if y > r then (y, x) : f (x + 1) y else f (x + 1) r
where y = a008480 x
CROSSREFS
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Nov 18 2015
STATUS
approved