A007094 - OEIS

A007094

Numbers in base 8.
(Formerly M0498)

221

0, 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 20, 21, 22, 23, 24, 25, 26, 27, 30, 31, 32, 33, 34, 35, 36, 37, 40, 41, 42, 43, 44, 45, 46, 47, 50, 51, 52, 53, 54, 55, 56, 57, 60, 61, 62, 63, 64, 65, 66, 67, 70, 71, 72, 73, 74, 75, 76, 77, 100, 101, 102, 103, 104, 105, 106, 107, 110, 111

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,3

REFERENCES

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

LINKS

Nathaniel Johnston, Table of n, a(n) for n = 0..10000

Wikipedia, Octal

R. G. Wilson, V, Letter to N. J. A. Sloane, Sep. 1992

Index entries for 10-automatic sequences.

FORMULA

a(0) = 0; a(n) = 10*a(n/8) if n == 0 (mod 8); a(n) = a(n-1) + 1 otherwise. - Benoit Cloitre, Dec 22 2002

G.f.: sum(d>=0, 10^d*(x^(8^d) +2*x^(2*8^d) +3*x^(3*8^d) +4*x^(4*8^d) +5*x^(5*8^d) +6*x^(6*8^d) +7*x^(7*8^d)) * (1-x^(8^d)) / ((1-x^(8^(d+1)))*(1-x))). - Robert Israel, Aug 03 2014

MAPLE

A007094 := proc(n) local l: if(n=0)then return 0: fi: l:=convert(n, base, 8): return op(convert(l, base, 10, 10^nops(l))): end: seq(A007094(n), n=0..66); # Nathaniel Johnston, May 06 2011

MATHEMATICA

Table[FromDigits[IntegerDigits[n, 8]], {n, 0, 70}]

PROG

(PARI) a(n)=if(n<1, 0, if(n%8, a(n-1)+1, 10*a(n/8)))

(PARI) apply( A007094(n)=fromdigits(digits(n, 8)), [0..77]) \\ M. F. Hasler, Nov 18 2019

(Haskell)

a007094 0 = 0

a007094 n = 10 * a007094 n' + m where (n', m) = divMod n 8

-- Reinhard Zumkeller, Aug 29 2013

(Python)

def a(n): return int(oct(n)[2:])

print([a(n) for n in range(74)]) # Michael S. Branicky, Jun 28 2021