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A215090 a(n) = Sum_{i=0..m} d(i)*3^i, where Sum_{i=0..m} d(i)*4^i is the base-4 representation of n. 4
0, 1, 2, 3, 3, 4, 5, 6, 6, 7, 8, 9, 9, 10, 11, 12, 9, 10, 11, 12, 12, 13, 14, 15, 15, 16, 17, 18, 18, 19, 20, 21, 18, 19, 20, 21, 21, 22, 23, 24, 24, 25, 26, 27, 27, 28, 29, 30, 27, 28, 29, 30, 30, 31, 32, 33, 33, 34, 35, 36, 36, 37, 38, 39, 27, 28, 29, 30, 30, 31, 32 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Seiichi Manyama, Table of n, a(n) for n = 0..10000 (terms 0..1000 from Clark Kimberling)

FORMULA

a(n) = 3*a(n/4) if n = 0 mod 4; otherwise a(n) = a(n-1)+1.

MATHEMATICA

t = Table[FromDigits[RealDigits[n, 4], 3], {n, 0, 100}]

PROG

(PARI) a(n) = fromdigits(digits(n, 4), 3); \\ Michel Marcus, May 02 2018

CROSSREFS

Cf. A023717.

Sequence in context: A248231 A120503 A215781 * A083544 A057353 A076539

Adjacent sequences:  A215087 A215088 A215089 * A215091 A215092 A215093

KEYWORD

nonn,base,easy

AUTHOR

Clark Kimberling, Aug 03 2012

STATUS

approved

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Last modified February 28 11:08 EST 2020. Contains 332323 sequences. (Running on oeis4.)