A037023 - OEIS

%I #22 Aug 30 2023 05:20:43

%S 1,1,4,1,7,3,2,0,0,0,2,2,3,6,1,2,4,4,9,4,9,2,6,4,5,7,5,1,2,8,2,8,4,2,

%T 7,1,3,0,0,0,0,0,0,0,0,3,1,6,2,2,7,7,6,6,0,3,3,1,6,6,2,4,7,9,0,4,3,4,

%U 6,4,1,0,1,6,1,5,1,4,3,6,0,5,5,5,1,2,7,5,4,6,4,3,7,4,1,6,5,7,3

%N Triangle in which row n lists the first n digits of sqrt(n) (rounded).

%H T. D. Noe, <a href="/A037023/b037023.txt">Rows n = 1..100 of triangle, flattened</a>

%e Triangle begins:

%e   1;

%e   1, 4;

%e   1, 7, 3;

%e   2, 0, 0, 0;

%e   2, 2, 3, 6, 1;

%e   2, 4, 4, 9, 4, 9;

%e   2, 6, 4, 5, 7, 5, 1;

%e   2, 8, 2, 8, 4, 2, 7, 1;

%e   3, 0, 0, 0, 0, 0, 0, 0, 0;

%e   3, 1, 6, 2, 2, 7, 7, 6, 6, 0;

%e   3, 3, 1, 6, 6, 2, 4, 7, 9, 0, 4;

%e   3, 4, 6, 4, 1, 0, 1, 6, 1, 5, 1, 4;

%e   3, 6, 0, 5, 5, 5, 1, 2, 7, 5, 4, 6, 4;

%e   ...

%t sds[n_]:=Module[{c=RealDigits[Sqrt[n],10,n+1][[1]]},If[Last[c]<5, Most[c], IntegerDigits[ FromDigits[Most[c]]+1]]]; Flatten[Array[sds,20]] (* _Harvey P. Dale_, Dec 13 2011 *)

%Y Cf. A037022.

%K nonn,base,nice,easy,tabl

%O 1,3

%A Jonas Persson (jptmp(AT)hotmail.com), _N. J. A. Sloane_