A102664 Lexically least sequence of distinct positive integers such that for all j and k, 1+a(j)-a(k) is 0, 1 or not a square.

1, 2, 3, 7, 8, 12, 13, 14, 19, 24, 30, 35, 40, 41, 46, 52, 53, 57, 58, 63, 69, 74, 79, 80, 85, 86, 90, 91, 96, 97, 108, 119, 124, 130, 135, 136, 141, 147, 158, 163, 164, 174, 186, 191, 213, 224, 245, 288, 297, 299, 316, 322, 327, 338, 339, 349, 350, 355, 366, 383, 389

Offset

1,2

Comments

Build up an array in which the rows are the numbers n^2 + k - 1, where k is the smallest number that has not yet been covered:

1, 4, 9,16,25,...

2, 5,10,17,26,...

3, 6,11,18,27,...

7,10,15,22,...

8,11,16,23,...

12,15,20,27,...

13,16,21,28,...

14,17,22,29,...

19,22,27,...

24,27,...

30,...

Sequence gives first column.

Links

Table of n, a(n) for n=1..61.

Crossrefs

Cf. A030193.

Sequence in context: A287675 A273944 A214324 * A055053 A233998 A047221

Adjacent sequences: A102661 A102662 A102663 * A102665 A102666 A102667

Keyword

nonn,easy

Author

Brendan McKay and Don Reble, Jan 27 2005

Extensions

More terms from David Wasserman, Apr 09 2008

Status

approved