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A247878 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}. 3
2, 39, 4180, 410780, 71114370, 16188759706, 35203970802248, 150323470036510005, 101010122201413121110, 82142319855341886460705, 86125744399762145472931164, 98834976539539763693131785850, 132929923088954538537350244463306, 205447801545228436007113806273864240 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,1

COMMENTS

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.

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 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.

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

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Last modified August 18 13:12 EDT 2019. Contains 326100 sequences. (Running on oeis4.)