A111445 Triangle read by rows: row n contains the first n numbers whose squares end in n^2.

1, 2, 8, 3, 7, 13, 4, 46, 54, 96, 5, 15, 25, 35, 45, 6, 44, 56, 94, 106, 144, 7, 43, 57, 93, 107, 143, 157, 8, 42, 58, 92, 108, 142, 158, 192, 9, 41, 59, 91, 109, 141, 159, 191, 209, 10, 90, 110, 190, 210, 290, 310, 390, 410, 490, 11, 239, 261, 489, 511, 739, 761, 989, 1011, 1239, 1261

Offset

1,2

Links

Alois P. Heinz, Rows n = 1..141, flattened

Formula

a(n) = A111444(n)^(1/2). - Michel Marcus, Sep 16 2013

Example

Triangle begins:
1;
2,  8;
3,  7, 13;
4, 46, 54, 96;
5, 15, 25, 35, 45;

Maple

p:=proc(n) local A, k: A:={}: for k from n to 3000 do if type((k^2-n^2)/10^(nops(convert(n^2, base, 10))), integer)=true then A:=A union {k} else A:=A: fi od: seq(A[j], j=1..n): end: for n from 1 to 11 do p(n) od; # yields sequence in triangular form, Emeric Deutsch, Aug 05 2005

Mathematica

row[n_] := Reap[For[k = n; cnt = 0, cnt < n, k++, idn = IntegerDigits[n^2] // Reverse; idk = IntegerDigits[k^2] // Reverse; If[idk[[;; Length[idn]]] == idn, cnt++; Sow[k]]]][[2, 1]];
Array[row, 11] // Flatten (* Jean-François Alcover, Dec 08 2019 *)

Crossrefs

Sequence in context: A337570 A190732 A081349 * A076696 A011057 A082236

Adjacent sequences: A111442 A111443 A111444 * A111446 A111447 A111448

Keyword

base,nonn,tabl,look

Author

Amarnath Murthy, Aug 03 2005

Extensions

More terms from Emeric Deutsch, Aug 05 2005

Status

approved