OFFSET
0,3
LINKS
Reinhard Zumkeller, Rows n = 0..1000 of triangle, flattened
Eric Weisstein's World of Mathematics, Ternary.
Wikipedia, Ternary numeral system.
EXAMPLE
Triangle begins:
0
1
2
0, 1
1, 1
2, 1
0, 2
1, 2
2, 2
0, 0, 1
1, 0, 1
2, 0, 1
0, 1, 1
1, 1, 1
2, 1, 1
...
MAPLE
A030341_row := n -> op(convert(n, base, 3)):
seq(A030341_row(n), n=0..32); # Peter Luschny, Nov 28 2017
MATHEMATICA
Flatten[Table[Reverse[IntegerDigits[n, 3]], {n, 0, 40}]] (* Harvey P. Dale, Oct 20 2014 *)
PROG
(Haskell)
a030341 n k = a030341_tabf !! n !! k
a030341_row n = a030341_tabf !! n
a030341_tabf = iterate succ [0] where
succ [] = [1]
succ (2:ts) = 0 : succ ts
succ (t:ts) = (t + 1) : ts
-- Reinhard Zumkeller, Feb 21 2013
(PARI) A030341(n, k=-1)=/*k<0&&error("Flattened sequence not yet implemented.")*/n\3^k%3 \\ Assuming that columns are numbered starting with k=0 as in A030308, A030567 and others. - M. F. Hasler, Jul 21 2013
(Python)
from gmpy2 import digits
from oeis_sequences.OEISsequences import bisection, bsearch
def A030341(n):
if n < 3: return n
def g(x): return x+(m:=len(digits(x, 3)))*(x+1)-(3**m-3>>1)
def f(x): return n+1+bsearch(g, x)
return int((s:=digits(a:=bisection(f, n+1, n+1)-n, 3))[(k:=len(s))*(a+1)-n-(3**k-1>>1)]) # Chai Wah Wu, Mar 04 2026
CROSSREFS
KEYWORD
nonn,base,tabf,less
AUTHOR
EXTENSIONS
Initial 0 and better name by Philippe Deléham, Oct 20 2011
STATUS
approved