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 A004492 Tersum n + 3. 0
 3, 4, 5, 6, 7, 8, 0, 1, 2, 12, 13, 14, 15, 16, 17, 9, 10, 11, 21, 22, 23, 24, 25, 26, 18, 19, 20, 30, 31, 32, 33, 34, 35, 27, 28, 29, 39, 40, 41, 42, 43, 44, 36, 37, 38, 48, 49, 50, 51, 52, 53, 45, 46, 47, 57, 58, 59, 60 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 LINKS FORMULA Tersum m + n : write m and n in base 3 and add mod 3 with no carries, e.g. 5 + 8 = "21" + "22" = "10" = 1. a(n)= -7 + Sum_{k=0..n}{(1/36)*(-35*(k mod 9)+((k+1) mod 9)-35*((k+2) mod 9)+37*((k+3) mod 9)+((k+4) mod 9)+((k+5) mod 9)+((k+6) mod 9)+((k+7) mod 9)+37*((k+8) mod 9)},with n>=0 - Paolo P. Lava, Dec 03 2007 CROSSREFS Sequence in context: A121151 A088243 A154660 * A140255 A050270 A202307 Adjacent sequences:  A004489 A004490 A004491 * A004493 A004494 A004495 KEYWORD nonn AUTHOR STATUS approved

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Last modified June 15 17:43 EDT 2019. Contains 324142 sequences. (Running on oeis4.)