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A059249
Tersum n + (n-1); write n and n-1 in base 3 and add mod 3 with no carries.
2
1, 0, 5, 7, 6, 2, 4, 3, 17, 19, 18, 23, 25, 24, 20, 22, 21, 8, 10, 9, 14, 16, 15, 11, 13, 12, 53, 55, 54, 59, 61, 60, 56, 58, 57, 71, 73, 72, 77, 79, 78, 74, 76, 75, 62, 64, 63, 68, 70, 69, 65, 67, 66, 26, 28, 27, 32, 34, 33, 29, 31, 30, 44, 46, 45, 50, 52, 51, 47, 49, 48, 35
OFFSET
1,3
LINKS
EXAMPLE
a(21)=14 since 21 and 20 are written in base 3 as 210 and 202 and so their tersum is 112 in base 3, i.e. 9+3+2=14.
CROSSREFS
KEYWORD
nonn,look
AUTHOR
Henry Bottomley, Jan 22 2001
STATUS
approved