A076698 a(1) = 2, a(n+1) = smallest squarefree number == 1 (mod a(n)).

2, 3, 7, 15, 31, 94, 95, 191, 383, 767, 1535, 3071, 6143, 12287, 36862, 36863, 73727, 147455, 294911, 589823, 1179647, 2359295, 4718591, 9437183, 18874367, 37748735, 75497471, 150994943, 301989887, 905969662, 905969663, 1811939327

Offset

1,1

Links

Table of n, a(n) for n=1..32.

Maple

with(numtheory):a[1] := 2:for n from 2 to 84 do q := a[n-1]+1:while(not issqrfree(q)) do q := q+a[n-1]:od:a[n] := q:od:seq(a[l], l=1..84);

Mathematica

a[1] = 2; a[n_] := a[n] = Block[{k = 1}, While[ MoebiusMu[k*a[n - 1] + 1] == 0, k++ ]; k*a[n - 1] + 1]; Table[ a[n], {n, 1, 32}]

Crossrefs

Sequence in context: A177487 A153010 A076993 * A323598 A078007 A368410

Adjacent sequences: A076695 A076696 A076697 * A076699 A076700 A076701

Keyword

nonn

Author

Amarnath Murthy, Oct 26 2002

Extensions

Edited and extended by Robert G. Wilson v, Oct 29 2002

Status

approved