A007093 - OEIS

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A007093

Numbers in base 7.
(Formerly M0511)

198

0, 1, 2, 3, 4, 5, 6, 10, 11, 12, 13, 14, 15, 16, 20, 21, 22, 23, 24, 25, 26, 30, 31, 32, 33, 34, 35, 36, 40, 41, 42, 43, 44, 45, 46, 50, 51, 52, 53, 54, 55, 56, 60, 61, 62, 63, 64, 65, 66, 100, 101, 102, 103, 104, 105, 106, 110, 111, 112, 113, 114, 115, 116, 120

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

OFFSET

0,3

REFERENCES

Albert H. Beiler, Recreations in the theory of numbers, New York, Dover, (2nd ed.) 1966. See p. 67.

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

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/7) if n==0 (mod 7), a(n) = a(n-1)+1 otherwise. - Benoit Cloitre, Dec 22 2002

MAPLE

A007093 := proc(n) local l: if(n=0)then return 0: fi: l:=convert(n, base, 7): return op(convert(l, base, 10, 10^nops(l))): end: seq(A007093(n), n=0..63); # Nathaniel Johnston, May 06 2011

MATHEMATICA

Table[ FromDigits[ IntegerDigits[n, 7]], {n, 0, 66}]

PROG

(PARI) a(n)=if(n<1, 0, if(n%7, a(n-1)+1, 10*a(n/7)))

(PARI) a(n) = fromdigits(digits(n, 7)); \\ Michel Marcus, Aug 12 2018

CROSSREFS

Cf. A000042, A007088, A007089, A007090, A007091, A007092, A007094, A007095.

Sequence in context: A143693 A143694 A037476 * A285469 A302706 A047423

Adjacent sequences: A007090 A007091 A007092 * A007094 A007095 A007096

KEYWORD

nonn,easy,base

AUTHOR

N. J. A. Sloane, Robert G. Wilson v

STATUS

approved