A060713 Smallest number whose sum of digits is 5^n.

1, 5, 799, 89999999999999, 4999999999999999999999999999999999999999999999999999999999999999999999

Offset: 0

Author

Robert G. Wilson v, Apr 21 2001

Keywords

• nonn
• base

Links

• Harry J. Smith, Table of n, a(n) for n = 0..5

Crossrefs

Cf. A051885, A060712.

Programs

Mathematica

Do[ a = {}; While[ Apply[ Plus, a ] + 9 < 5^n, a = Append[ a, 9 ] ]; If[ Apply[ Plus, a ] != 5^n, a = Prepend[ a, 5^n - Apply[ Plus, a ] ] ]; Print[ FromDigits[ a ] ], {n, 1, 4} ]

PARI

a(n)={ my(s=5^n, x=s\9, d=s-9*x); (d+1)*10^x - 1 } \\ Harry J. Smith, Jul 10 2009

Formula

a(n) = A051885(5^n).