A076164 Numbers n such that sum of squares of even digits of n equals sum of squares of odd digits of n.

0, 11112, 11121, 11211, 11356, 11365, 11536, 11563, 11635, 11653, 12111, 13156, 13165, 13516, 13561, 13615, 13651, 15136, 15163, 15316, 15361, 15613, 15631, 16135, 16153, 16315, 16351, 16513, 16531, 21111, 31156, 31165, 31516, 31561

Offset: 1

Author

Zak Seidov, Nov 01 2002

Keywords

• nonn
• base

Comments

The minimal number of digits in any nonzero term is 5.

Numbers such that the sum of even digits equals the sum of odd digits are listed in A036301.

Examples

			11356 is in the sequence because 1^2 + 1^2 + 3^2 + 5^2 = 6^2.
		

Crossrefs

Cf. A303269, A036301 (analog without squares), A071650, A304439, A304440, A124176, A124177.

Programs

Mathematica

oeQ[n_]:=Module[{idn=IntegerDigits[n]},Total[Select[idn,OddQ]^2]== Total[ Select[ idn, EvenQ]^2]]; Select[Range[0,99999],oeQ] (* Harvey P. Dale, Sep 23 2011 *)

PARI

is(n)=!vecsum(apply(d->d^2*(-1)^d,digits(n))) \\ M. F. Hasler, May 18 2018

Extensions

Edited and a(1) = 0 added by M. F. Hasler, May 18 2018