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

1,3

Links

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

Example

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.

Prog

(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, ", ") ) )

Crossrefs

Sequence in context: A295951 A083944 A306106 * A328780 A184261 A095919

Adjacent sequences: A165547 A165548 A165549 * A165551 A165552 A165553

Keyword

base,easy,nonn

Author

Rémy Sigrist, Sep 21 2009

Extensions

Offset fixed by Rémy Sigrist, Feb 03 2017

Status

approved