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A242407
Numbers such that in ternary representation all pairs of adjacent digits have sums not greater than 2.
6
0, 1, 2, 3, 4, 6, 9, 10, 11, 12, 13, 18, 19, 20, 27, 28, 29, 30, 31, 33, 36, 37, 38, 39, 40, 54, 55, 56, 57, 58, 60, 81, 82, 83, 84, 85, 87, 90, 91, 92, 93, 94, 99, 100, 101, 108, 109, 110, 111, 112, 114, 117, 118, 119, 120, 121, 162, 163, 164, 165, 166, 168
OFFSET
1,3
COMMENTS
A242400(a(n)) = 0;
A242399(a(n)) = 4*a(n);
numbers m, such that in ternary arithmetic no carry occurs, when 3*m is added to m.
LINKS
Eric Weisstein's World of Mathematics, Ternary.
EXAMPLE
Initial terms and their ternary representations, cf. A007089:
. 0 1 2 3 4 6 9 10 11 12 13 18 19 20 27 28 29 30 ..
. 0 1 2 10 11 20 100 101 102 110 111 200 201 202 1000 1001 1002 1010 ..
MATHEMATICA
Select[Range[0, 200], Max[Total/@Partition[IntegerDigits[#, 3], 2, 1]]<3&] (* Harvey P. Dale, Jan 08 2023 *)
PROG
(Haskell)
a242407 n = a242407_list !! (n-1)
a242407_list = filter ((== 0) . a242400) [0..]
CROSSREFS
Cf. A242408 (complement), A003714, A039691, A007089.
Sequence in context: A334860 A082976 A343382 * A047419 A135205 A145733
KEYWORD
nonn,base
AUTHOR
Reinhard Zumkeller, May 13 2014
STATUS
approved