OFFSET
1,2
COMMENTS
LINKS
FORMULA
EXAMPLE
The top left corner of array A277820 is:
1, 3, 5, 15
2, 6, 10, 30
7, 9, 27, 45
4, 12, 20, 60
13, 23, 57, 75
while the top left corner of A277880 is:
1, 3, 6, 12
2, 5, 10, 20
4, 9, 18, 36
7, 15, 30, 60
8, 17, 34, 68
thus for example, a(1) = 1, a(2) = 2, a(3) = 3, a(4) = 7, a(5) = 6, a(6) = 5, a(7) = 4, a(9) = 9, a(12) = 15, a(13) = 8 and a(27) = 18.
PROG
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Antti Karttunen, Nov 03 2016
STATUS
approved