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%I #12 Oct 31 2021 22:57:40
%S 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,
%T 2,1,9,9,9,9,9,9,9,9,9,1,2,3,4,5,6,7,8,9,1,2,4,6,8,1,3,5,7,9,2,4,3,6,
%U 9,3,6,9,3,6,9,3,6,9,4
%N Triangle read by rows: row n gives the numbers A010888(n*k) for k = 1..n.
%H Nathaniel Johnston, <a href="/A139413/b139413.txt">Table of n, a(n) for n = 1..10000</a>
%e Triangle begins:
%e 1
%e 2 4
%e 3 6 9
%e 4 8 3 7
%e 5 1 6 2 7
%e 6 3 9 6 3 9
%e 7 5 3 1 8 6 4
%e 8 7 6 5 4 3 2 1
%e 9 9 9 9 9 9 9 9 9
%e ...
%p A010888:=proc(n) return ((n-1) mod 9)+1; end:
%p 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
%t Table[FixedPoint[Total@ IntegerDigits[#] &, n k], {n, 13}, {k, n}] // Flatten (* _Michael De Vlieger_, Oct 31 2021 *)
%Y Cf. A007953 (column 1), A180592 - A180599 (columns 2 - 9), A010888, A038194.
%K easy,nonn,tabl,base
%O 1,2
%A Philippe Lallouet (philip.lallouet(AT)orange.fr), Apr 19 2008
%E More terms and several terms corrected by _Nathaniel Johnston_, Apr 21 2011
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