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a(n) is the least integer m such that the sum of the digits of m^2 is k+n where k is the number of digits of n.
1

%I #13 Feb 20 2024 10:41:25

%S 1,101,11,2,149,32,4,12,3,8,106,16,7,103,13,108,24,17,1019,124,43,

%T 1013,113,67,114,63,10024,1024,133,83,1067,167,1044,264,314,10087,

%U 1303,313,10093,1183,707,1374,1333,836,10343,1667,100264,10714,2236,10386,3114

%N a(n) is the least integer m such that the sum of the digits of m^2 is k+n where k is the number of digits of n.

%H Zhining Yang, <a href="/A369956/b369956.txt">Table of n, a(n) for n = 0..152</a>

%e a(5)=32 because 32 is the least integer with 2 digits and 32^2=1024 and 1+0+2+4=2+5.

%t Table[SelectFirst[Range@200000,Total[IntegerDigits[#^2]]==n+Length@IntegerDigits@#&],{n,0,50}]

%Y Cf. A004159, A369953, A369955.

%K nonn,base,easy

%O 0,2

%A _Zhining Yang_, Feb 06 2024