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A247878
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For bases b = 2, 3, ..., n, let the base-b expansion of n be [c_{1,b} c_{2,b} .. c_{r_b,b}], with the most significant "digit" on the left, 0 <= c_{i,b} < b, and c_{1,b} != 0; then a(n) is the number whose base-n expansion is c_{1,2} c_{2,2} ... c_{r_2,2} c_{1,3} ... c_{1,n} c_{2,n} ... c_{r_n,n}.
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%I #27 Oct 02 2014 14:01:29
%S 2,39,4180,410780,71114370,16188759706,35203970802248,
%T 150323470036510005,101010122201413121110,82142319855341886460705,
%U 86125744399762145472931164,98834976539539763693131785850,132929923088954538537350244463306,205447801545228436007113806273864240
%N For bases b = 2, 3, ..., n, let the base-b expansion of n be [c_{1,b} c_{2,b} .. c_{r_b,b}], with the most significant "digit" on the left, 0 <= c_{i,b} < b, and c_{1,b} != 0; then a(n) is the number whose base-n expansion is c_{1,2} c_{2,2} ... c_{r_2,2} c_{1,3} ... c_{1,n} c_{2,n} ... c_{r_n,n}.
%C The base-n expansion of a(n) is the concatenations of the expansions of n in bases 2, 3, ..., n-1, n, regarding all the coefficients as numbers in the range 0 to n-1.
%H Hiroaki Yamanouchi, <a href="/A247878/b247878.txt">Table of n, a(n) for n = 2..100</a>
%e For n = 4, we first find 4 in base 2 = 1,0,0, then 4 in base 3 = 1,1, and 4 in base 4 = 1,0. The full string we now have is '1,0,0,1,1,1,0', which is the base-4 expansion of the number a(4) = 1*4^6 + 0*4^5 + 0*4^4 + 1*4^3 + 1*4^2 + 1*4^1 + 0*4^0 = 4180.
%Y Cf. A247873, A247880.
%K nonn,base,easy
%O 2,1
%A _Talha Ali_, Sep 25 2014
%E Definition revised by _N. J. A. Sloane_, Sep 27 2014
%E a(7)-a(15) from _Hiroaki Yamanouchi_, Oct 02 2014
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