A165550 Sum of digits of square is sum of square of digits.

0, 1, 2, 3, 10, 20, 30, 33, 100, 200, 300, 330, 333, 1000, 1143, 1431, 2000, 2242, 3000, 3233, 3300, 3330, 3331, 3333, 3411, 3433, 4131, 10000, 11234, 11243, 11344, 11403, 11430, 11432, 11433, 12235, 12523, 13134, 13142, 13144, 13241, 13431, 13522

Offset: 1

Author

Rémy Sigrist, Sep 21 2009

Keywords

• base
• easy
• nonn

Examples

			Consider n=33: n^2 is 1089, sum of square of digits is 3^2+3^2=18, and sum of digits of square is 1+0+8+9=18, thus 33 appears in the sequence.
		

Links

• Rémy Sigrist, Table of n, a(n) for n = 1..10000

Programs

PARI

digsum(n) = my(s=0); while(n,s=s+n%10;n=n\10); s;
sqadigsum(n) = my(s=0); while(n,s=s+(n%10)^2;n=n\10); s;
for(n=0,100000, if(sqadigsum(n)==digsum(n^2), print1(n, ",") ) )

Extensions

Offset fixed by Rémy Sigrist, Feb 03 2017