A220476 Let a(0)=1. For n > 0, a(n) is the least integer greater than a(n-1) such that the polynomial 1/a(0) + x^1/a(1) +...+ x^n/a(n) has exactly n distinct real roots.

1, 2, 17, 495, 47208, 14600027, 14610226398, 47283768063238

Offset

0,2

Links

Table of n, a(n) for n=0..7.

Example

 1+x/2 has 1 real root. Then a(2)=17 is the least value > 2 such that 1+x/2+x^2/a(2) has 2 distinct real roots.

Crossrefs

Sequence in context: A308864 A370704 A217284 * A293178 A367831 A367829

Adjacent sequences: A220473 A220474 A220475 * A220477 A220478 A220479

Keyword

nonn,more

Author

Benoit Cloitre, Dec 15 2012

Status

approved