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A049548 a(n+1) = smallest number not containing any digits of a(n), working in base 4. 0
0, 1, 2, 3, 4, 10, 12, 21, 32, 53, 128, 213, 512, 853, 2048, 3413, 8192, 13653, 32768, 54613, 131072, 218453, 524288, 873813, 2097152, 3495253, 8388608, 13981013, 33554432, 55924053, 134217728, 223696213, 536870912, 894784853, 2147483648 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..34.

Index entries for linear recurrences with constant coefficients, signature (0,5,0,-4).

FORMULA

For n>9, a(n)=4*a(n-2) + (a(n-2) mod 4).

a(n) = 5*a(n-2)-4*a(n-4) for n>5; g.f.: x*(32*x^10+16*x^9-12*x^8-12*x^7-17*x^6-x^4-6*x^3-2*x^2+2*x+1) / ((x-1)*(x+1)*(2*x-1)*(2*x+1)). - Colin Barker, Sep 13 2014

EXAMPLE

Written in base 4 the sequence appears as 0, 1, 2, 3, 10, 22, 30, 111, 200, 311, 2000, 3111, 20000, 31111, 200000, 311111, 2000000, 3111111, etc. So a(9)=311 base 4 =53 base 10.

MATHEMATICA

LinearRecurrence[{0, 5, 0, -4}, {0, 1, 2, 3, 4, 10, 12, 21, 32, 53, 128, 213}, 40] (* Harvey P. Dale, Apr 27 2020 *)

CROSSREFS

Cf. A030283, A030439.

Sequence in context: A196007 A134170 A276560 * A005456 A100773 A250112

Adjacent sequences:  A049545 A049546 A049547 * A049549 A049550 A049551

KEYWORD

base,easy,nonn

AUTHOR

Henry Bottomley, Dec 28 2000

STATUS

approved

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Last modified September 24 08:44 EDT 2020. Contains 337317 sequences. (Running on oeis4.)