A230356 - OEIS

%I #9 Dec 11 2015 12:44:50

%S 10,18,27,40,45,54,63,72,90,108,117,126,135,153,160,162,171,180,207,

%T 216,220,234,243,250,252,261,270,304,306,315,333,342,351,360,405,414,

%U 423,432,450,490,504,513,522,531,540,603,612,621,630,640,702,711,720,801,810,931

%N Nonsquare numbers n such that digit sum of n = digit sum of square part of n.

%e 135 = 2^3*5. Square part of 135 is 9. Digit_sum(135) =9, digit_sum(9) = 9.

%o (PARI)

%o digsum(n)={local (d, p); d=0; p=n; while(p, d+=p%10; p=floor(p/10)); return(d)}

%o {for (n=2, 10^3,m=n/core(n);if(digsum(n)==digsum(m)&&m<>n,print(n)));}

%Y Cf. A006753, A230354, A230355, A230357.

%K nonn,base,less

%O 1,1

%A _Antonio Roldán_, Oct 16 2013