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Write 0, 1, ..., n in base 3 and add as if they were decimal numbers.
1

%I #5 Oct 31 2013 12:17:40

%S 0,1,3,13,24,36,56,77,99,199,300,402,512,623,735,855,976,1098,1298,

%T 1499,1701,1911,2122,2334,2554,2775,2997,3997,4998,6000,7010,8021,

%U 9033,10053,11074,12096,13196,14297,15399,16509,17620,18732,19852,20973,22095

%N Write 0, 1, ..., n in base 3 and add as if they were decimal numbers.

%C This is to A007089 as A067894 is to A007088.

%e a(5) = 36 = 0 + 1 + 2 + 10 + 11 + 12.

%t f[n_] := Apply[Plus, Table[ FromDigits[ IntegerDigits[i, 3]], {i, 0, n}]]; Table[ f@n, {n, 0, 45}] (* _Robert G. Wilson v_ Sep 10 2006 *)

%Y Cf. A007088, A007089, A067894.

%K base,easy,nonn

%O 0,3

%A _Jonathan Vos Post_, Sep 08 2006