A157606 a(1)=1. a(n) = the largest integer coprime to a(n-1) and less than n^2.

1, 3, 8, 15, 23, 35, 48, 61, 80, 99, 119, 143, 168, 193, 224, 255, 287, 323, 360, 397, 440, 483, 527, 575, 624, 673, 728, 783, 839, 899, 960, 1021, 1088, 1155, 1223, 1295, 1368, 1441, 1520, 1599, 1679, 1763, 1848, 1933, 2024, 2115, 2207, 2303, 2400, 2497, 2600

Offset

1,2

Links

Table of n, a(n) for n=1..51.

Mathematica

a[n_] := a[n] = Block[{k = n^2 - 1}, While[ GCD[k, a[n - 1]] > 1, k-- ]; k]; a[1] = 1; Array[a, 55] (* Robert G. Wilson v, May 04 2009 *)

Crossrefs

Cf. A157421, A157604, A157605.

Sequence in context: A294399 A331943 A064356 * A359056 A191414 A086959

Adjacent sequences: A157603 A157604 A157605 * A157607 A157608 A157609

Keyword

nonn

Author

Leroy Quet, Mar 02 2009

Extensions

More terms from Robert G. Wilson v, May 04 2009

Status

approved