login
Numbers n that are not multiples of 10 such that sum of digits of n^2 is 7.
2

%I #18 Aug 21 2022 19:31:13

%S 4,5,32,49,149,1049

%N Numbers n that are not multiples of 10 such that sum of digits of n^2 is 7.

%C Sequence is complete.

%C Except for the number 1, these six and numbers 10^k+1 (A062397) are the only numbers (up to trailing 0's) whose square has sum of digits less than 9. - _M. F. Hasler_, Sep 23 2014

%t Select[Range[1500],Mod[#,10]!=0&&Total[IntegerDigits[#^2]]==7&] (* _Harvey P. Dale_, Aug 21 2022 *)

%o (PARI) for(n=1,9e9,n%10&&sumdigits(n^2)==7&&print1(n",")) \\ _M. F. Hasler_, Sep 23 2014

%Y Cf. A004159 = Sum of digits of n^2.

%K nonn,base,fini,full

%O 1,1

%A _Zak Seidov_, Aug 17 2012