OFFSET
1,2
LINKS
Nathaniel Johnston, Table of n, a(n) for n = 1..10000
EXAMPLE
Triangle begins:
1
2 4
3 6 9
4 8 3 7
5 1 6 2 7
6 3 9 6 3 9
7 5 3 1 8 6 4
8 7 6 5 4 3 2 1
9 9 9 9 9 9 9 9 9
...
MAPLE
A010888:=proc(n) return ((n-1) mod 9)+1; end:
for n from 1 to 9 do for k from 1 to n do printf("%d ", A010888(n*k)); od: printf("\n"): od: # Nathaniel Johnston, Apr 21 2011
MATHEMATICA
Table[FixedPoint[Total@ IntegerDigits[#] &, n k], {n, 13}, {k, n}] // Flatten (* Michael De Vlieger, Oct 31 2021 *)
CROSSREFS
KEYWORD
AUTHOR
Philippe Lallouet (philip.lallouet(AT)orange.fr), Apr 19 2008
EXTENSIONS
More terms and several terms corrected by Nathaniel Johnston, Apr 21 2011
STATUS
approved