A281366 Lexicographically least strictly increasing sequence such that, for any n>0, Sum_{k=1..n} a(k) can be computed without carries in base 9 (the numbers are written in base 9).
1, 2, 3, 10, 11, 20, 21, 100, 110, 200, 210, 1000, 1100, 2000, 2100, 10000, 11000, 20000, 21000, 100000, 110000, 200000, 210000, 1000000, 1100000, 2000000, 2100000, 10000000, 11000000, 20000000, 21000000, 100000000, 110000000, 200000000, 210000000
Offset: 1
Links
- Colin Barker, Table of n, a(n) for n = 1..1000
- N. J. A. Sloane, Illustration of initial terms
- Index entries for linear recurrences with constant coefficients, signature (0,0,0,10).
Programs
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PARI
Vec(x*(1 + 2*x + 3*x^2 + 10*x^3 + x^4 - 9*x^6) / (1 - 10*x^4) + O(x^60)) \\ Colin Barker, Jan 29 2017
Formula
From Colin Barker, Jan 29 2017: (Start)
G.f.: x*(1 + 2*x + 3*x^2 + 10*x^3 + x^4 - 9*x^6)/(1 - 10*x^4).
a(n) = 10*a(n-4) for n>7. (End)
Extensions
More terms from Colin Barker, Jan 29 2017
Comments