

A247878


For bases b = 2, 3, ..., n, let the baseb 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 basen 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}.


3



2, 39, 4180, 410780, 71114370, 16188759706, 35203970802248, 150323470036510005, 101010122201413121110, 82142319855341886460705, 86125744399762145472931164, 98834976539539763693131785850, 132929923088954538537350244463306, 205447801545228436007113806273864240
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OFFSET

2,1


COMMENTS

The basen expansion of a(n) is the concatenations of the expansions of n in bases 2, 3, ..., n1, n, regarding all the coefficients as numbers in the range 0 to n1.


LINKS

Hiroaki Yamanouchi, Table of n, a(n) for n = 2..100


EXAMPLE

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 base4 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.


CROSSREFS

Cf. A247873, A247880.
Sequence in context: A177773 A274574 A212615 * A232086 A047660 A213909
Adjacent sequences: A247875 A247876 A247877 * A247879 A247880 A247881


KEYWORD

nonn,base,easy


AUTHOR

Talha Ali, Sep 25 2014


EXTENSIONS

Definition revised by N. J. A. Sloane, Sep 27 2014
a(7)a(15) from Hiroaki Yamanouchi, Oct 02 2014


STATUS

approved



