A288658 Numbers whose squares have an even number of digits.

4, 5, 6, 7, 8, 9, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92

Offset

1,1

Comments

The sequence of squares starts: 16, 25, 36, 49, 64, 81, 1024, 1089, 1156, 1225, 1296, ...

Links

Lars Blomberg, Table of n, a(n) for n = 1..10000

Jeremy Gardiner, Middle digit in square numbers, Seqfan Mailing list, Dec 12 2016.

Crossrefs

Cf. A288657, A288659, A288660.

Sequence in context: A084991 A356824 A099070 * A065342 A231369 A251392

Adjacent sequences: A288655 A288656 A288657 * A288659 A288660 A288661

Keyword

nonn,base,easy

Author

Lars Blomberg, Jun 13 2017

Status

approved