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A025632 Numbers of form 7^i*10^j, with i, j >= 0. 9
1, 7, 10, 49, 70, 100, 343, 490, 700, 1000, 2401, 3430, 4900, 7000, 10000, 16807, 24010, 34300, 49000, 70000, 100000, 117649, 168070, 240100, 343000, 490000, 700000, 823543, 1000000, 1176490, 1680700, 2401000, 3430000, 4900000, 5764801, 7000000 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

PROG

(Haskell)

import Data.Set (singleton, deleteFindMin, insert)

a025632 n = a025632_list !! (n-1)

a025632_list = f $ singleton (1, 0, 0) where

   f s = y : f (insert (7 * y, i + 1, j) $ insert (10 * y, i, j + 1) s')

         where ((y, i, j), s') = deleteFindMin s

-- Reinhard Zumkeller, May 15 2015

(PARI) list(lim)=my(v=List(), N); for(n=0, logint(lim\=1, 10), N=10^n; while(N<=lim, listput(v, N); N*=7)); Set(v) \\ Charles R Greathouse IV, Jan 10 2018

CROSSREFS

Cf. A025612, A025616, A025621, A025625, A025629, A025634, A025635, A108761, A003596, A003597, A107988, A003598, A108698, A003599, A107788, A108687, A108779, A108090.

Sequence in context: A013398 A013493 A166661 * A038276 A249952 A187999

Adjacent sequences:  A025629 A025630 A025631 * A025633 A025634 A025635

KEYWORD

easy,nonn

AUTHOR

David W. Wilson

STATUS

approved

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Last modified May 20 02:50 EDT 2019. Contains 323412 sequences. (Running on oeis4.)