A135029 Numbers k such that k and k^2 both have digit sum 10. Multiples of 10 are omitted.

19, 46, 55, 145, 361, 451, 20251

Offset: 1

Author

Zak Seidov, Feb 10 2008

Keywords

• base
• nonn

Comments

A subsequence of A056020. - R. J. Mathar, Feb 10 2008

No further terms < 3*10^12 of the form 9*k+1, k=1,2,3,... - Lars Blomberg, Jun 28 2011

No further terms < 10^30. - Charles R Greathouse IV, Jun 29 2011

Examples

			Corresponding squares are 361, 2116, 3025, 21025, 130321, 203401, 410103001.
		

Crossrefs

Cf. A056020.

Programs

PARI

dsum(n)=my(s=n%10);while(n\=10,s+=n%10);s
do(L)=my(E,F,G,H,t);for(a=1,L-1, for(b=0,a, for(c=0,b, for(d=0,c, for(e=0,d, E=10^a+10^b+10^c+10^d+10^e; for(f=0,e,F=E+10^f; for(g=0,f, G=F+10^g; for(h=0,g, H=G+10^h; for(i=0,h, t=H+10^i+1; if(dsum(t^2)==10, print1(t", ")))))))))));
do(30) \\ Charles R Greathouse IV, Jun 29 2011