|
%I #14 Apr 23 2022 14:56:23
%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.
%C 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.
%H Seiichi Manyama, <a href="/A097582/b097582.txt">Table of n, a(n) for n = 1..318</a>
%F a(n) = A007093(A007908(n)). - _Seiichi Manyama_, Apr 23 2022
%Y Cf. A007908, A050926, A097580, A097583.
%Y Cf. A007093.
%K base,nonn
%O 1,2
%A _Cino Hilliard_, Aug 29 2004
|
