A061104 Smallest number whose digit sum is n^2.

0, 1, 4, 9, 79, 799, 9999, 499999, 19999999, 999999999, 199999999999, 49999999999999, 9999999999999999, 7999999999999999999, 7999999999999999999999, 9999999999999999999999999

Offset

0,3

Links

Harry J. Smith, Table of n, a(n) for n = 0..94

Formula

a(n) = ((n^2 mod 9) + 1)*10^floor(n^2/9) - 1. - Henry Bottomley, Apr 24 2001

Example

a(5) = 799, 7 + 9 + 9 = 25 = 5^2.

Prog

(PARI) { for (n=0, 94, a=(n^2%9 + 1)*10^(n^2\9) - 1; write("b061104.txt", n, " ", a) ) } \\ Harry J. Smith, Jul 18 2009

Crossrefs

Cf. A051885, A061105.

Sequence in context: A041030 A361067 A359654 * A082381 A155931 A309801

Adjacent sequences: A061101 A061102 A061103 * A061105 A061106 A061107

Keyword

nonn,base

Author

Amarnath Murthy, Apr 20 2001

Status

approved