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 A089293 Sum of digits in the mixed-base enumeration system n=...d(4)d(3)d(2)d(1), where the digits satisfy 0<=d(i)<=1 if i is odd, 0<=d(i)<=2 if i is even. 1
 0, 1, 1, 2, 2, 3, 1, 2, 2, 3, 3, 4, 1, 2, 2, 3, 3, 4, 2, 3, 3, 4, 4, 5, 2, 3, 3, 4, 4, 5, 3, 4, 4, 5, 5, 6, 1, 2, 2, 3, 3, 4, 2, 3, 3, 4, 4, 5, 2, 3, 3, 4, 4, 5, 3, 4, 4, 5, 5, 6, 3, 4, 4, 5, 5, 6, 4, 5, 5, 6, 6, 7, 1, 2, 2, 3, 3, 4, 2, 3, 3, 4, 4, 5, 2, 3, 3, 4, 4, 5, 3, 4, 4, 5, 5, 6, 3, 4, 4, 5, 5, 6, 4, 5, 5 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,4 COMMENTS Counting 0,1,2,3,... (base 10) in this mixed-base system proceeds as follows: 0,1,10,11,20,21,100,101,110,111,120,121,1000,.. = A109827. LINKS FORMULA a(n)=a(n-1)+1 if n=1, 3, 5 mod 6; a(n)=a(n-1) if n=2, 4 mod 5; a(n)=a(n/6) if n=0 mod 6. EXAMPLE 11(base 10) = 121(mixed-base), so a(11)=4. PROG (PARI) a(n) = vecsum(digits(n, 6)\/2); \\ Kevin Ryde, Aug 03 2021 CROSSREFS Cf. A109827 (mixed-base). Sums of digits in other bases: A000120 (binary), A053735 (ternary), A053827 (base 6). Sequence in context: A299029 A200747 A328481 * A034968 A341513 A276150 Adjacent sequences:  A089290 A089291 A089292 * A089294 A089295 A089296 KEYWORD nonn,base,easy,less AUTHOR John W. Layman, Jan 15 2004 STATUS approved

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Last modified January 22 07:31 EST 2022. Contains 350481 sequences. (Running on oeis4.)