A007961 n written in base where place values are positive squares.

1, 2, 3, 10, 11, 12, 13, 20, 100, 101, 102, 103, 110, 111, 112, 1000, 1001, 1002, 1003, 1010, 1011, 1012, 1013, 1020, 10000, 10001, 10002, 10003, 10010, 10011, 10012, 10013, 10020, 10100, 10101, 100000, 100001, 100002, 100003, 100010, 100011

Offset: 1

Author

R. Muller

Keywords

• nonn
• base

Comments

For n>1: A000196(n) = number of digits of a(n); A190321(n) = number of nonzero digits of a(n); A053610(n) = sum of digits of a(n). [Reinhard Zumkeller, May 08 2011]

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
• F. Smarandache, Only Problems, Not Solutions!.

Crossrefs

Cf. A000290, A000433.

Programs

Haskell

import Data.Char (intToDigit)
a007961 :: Integer -> Integer
a007961 n = read $ map intToDigit $
  t n $ reverse $ takeWhile (<= n) $ tail a000290_list where
    t _ []          = []
    t m (x:xs)
        | x > m     = 0 : t m xs
        | otherwise = (fromInteger m') : t r xs
        where (m',r) = divMod m x
-- Reinhard Zumkeller, May 08 2011

Maple

A007961 := proc(n)
    local k,nrem,L,b,d;
    k := floor(sqrt(n)) ;
    nrem := n ;
    L := [] ;
    for b from k to 1 by -1 do
        d := floor(nrem/b^2) ;
        L := [d,op(L)] ;
        nrem := nrem -d*b^2 ;
    end do:
    add( op(i,L)*10^(i-1),i=1..nops(L)) ;
end proc: # R. J. Mathar, Jul 25 2015