A048557 a(1) = 1; a(n+1) is next smallest nontrivial square beginning with a(n).

1, 16, 169, 169744, 16974441796, 1697444179660172924176, 16974441796601729241768240010144800000000001, 1697444179660172924176824001014480000000000182400101448000000000020000000000000000000001

Offset

1,2

Comments

Next terms are 176, 351 and 702 digits long.

Links

Robert G. Wilson v, Table of n, a(n) for n = 1..11

Mathematica

$MaxExtraPrecision = 2^10; a[n_] := a[n] = Block[{k = 10, m = a[n - 1]}, id = IntegerDigits@ m; lng = Length@ id; While[c = Ceiling[ Sqrt[ m*k]]^2; Take[ IntegerDigits@ c, lng] != id, k *= 100]; Min[c, (Sqrt[m]*10^(lng/2) + 1)^2]]; a[1] = 1; Array[a, 11] (* Robert G. Wilson v, Dec 18 2014 *)

Crossrefs

Cf. A048558, A050628, A061110. See A048558 for the square roots.

Cf. A249893, A249894, A048559, A249895, A249896, A249897, A249898, A048561.

Sequence in context: A242078 A264092 A050628 * A174645 A021424 A200673

Adjacent sequences: A048554 A048555 A048556 * A048558 A048559 A048560

Keyword

nonn,base

Author

Patrick De Geest, May 15 1999

Status

approved