A126973 a(n+1) is the smallest integer greater than a(n) such that the sum of the squares of its decimal digits is equal to a(n).

1, 10, 13, 23, 1233, 33999999999999999

Offset: 1

Author

Paolo P. Lava and Giorgio Balzarotti, Mar 20 2007; corrected Mar 23 2007

Keywords

• nonn
• base

Examples

			10 --> 1^2+0^2 = 1+0 =1
13 --> 1^2+3^2 = 1+9 = 10
23 --> 2^2+3^2 = 4+9 =13
1233 --> 1^2+2^2+3^3+3^2 = 1+4+9+9 = 23
33999999999999999 = 3^2*2 + 9^2*15 = 1233
		

Crossrefs

Cf. A001273, A053612.

Extensions

Next term is greater than 10^419753086419753. [From Charles R Greathouse IV, Nov 13 2010]