This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A357894 #19 Nov 19 2022 21:22:26
%S A357894 0,1,6,10,14,18,27,33,41,43,46,55,56,62,66,69,70,77,80,87,93,98,102,
%T A357894 108,110,123,124,145,147,149,150,154,157,162,164,165,168,176,177,179,
%U A357894 180,182,183,197,204,213,214,219,224,236,237,242,248,251,252,261,262,263,271,274,285,295
%N A357894 Integers k such that the sum of some number of initial decimal digits of sqrt(k) is equal to k.
%C A357894 For integers k that are squares of integers, "Sum of initial digits" includes digits to the left of the decimal point only, as there are no digits other than zero to the right of the decimal point. This constraint contributes terms 0 and 1 to the sequence.
%C A357894 For integers k with irrational sqrt(k), "Sum of initial digits" includes digits to the left of the decimal point and to the right of the decimal point.
%C A357894 "Initial digits" implies a sufficient number of digits to produce either a sum > k or a sum = k condition, halting at whichever condition occurs first (sum > k condition is discarded).
%e A357894 41 is a term because sqrt(41) = 6.4031242374328... and 6+4+0+3+1+2+4+2+3+7+4+3+2 = 41.
%e A357894 42 is not a term because sqrt(42) = 6.480740698407860... and 6+4+8+0+7+4+0+6 = 35 and 6+4+8+0+7+4+0+6+9 = 44 (no sum of initial digits = 42).
%e A357894 144 is not a term because sqrt(144) = 12 (no digits to the right of the decimal), and 1+2 is not equal to 144.
%o A357894 (PARI) is(n) = { my (d=digits(sqrtint(n)), s=0); for (i=1, #d, s+=d[i]; if (s==n, return (1), s>n, return (0););); if (issquare(n), return (n==0);); my (n0=n); while (1, s+=sqrtint(n0*=100)%10; if (s==n, return (1), s>n, return (0););); } \\ _Rémy Sigrist_, Oct 19 2022
%Y A357894 Cf. A106039.
%K A357894 nonn,base
%O A357894 1,3
%A A357894 _Gil Broussard_, Oct 18 2022