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 A097582 Base 7 representation of the concatenation of the first n numbers with the most significant digits first. 0

%I

%S 1,15,234,3412,50664,1022634,13331215,206636142,3026236221,

%T 614636352655,155123512633260,35001313215554565,10403265603212022112,

%U 2132066345452131466644,434014101450663623262042

%N Base 7 representation of the concatenation of the first n numbers with the most significant digits first.

%F Consider numbers of the form 1, 12, 123, 1234, ..., N. Find the highest power of 7^p such that 7^p < N. Then p = [log(N)/log(7)] and for 0 <= qi <= 6 [N/7^p] = q1 + r1 [r1/7^(p-1)] = q2 + r2 ........................ rp/7^1 = qp + rp+1 rp+1/7^0 = qp+1 0 For N = 1234, p = [log(1234)/log(7)] = 3 division quot rem 1234/7^3 = 3 205 205/7^2 = 4 9 9/7^1 = 1 2 2/7^0 = 2 0 The sequence of quotients, top down, forms the entry in the table for 1234. Obviously this algorithm works for any N.

%K base,nonn

%O 1,2

%A _Cino Hilliard_, Aug 29 2004

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Last modified October 25 10:46 EDT 2021. Contains 348239 sequences. (Running on oeis4.)