A087334 a(1) = 3, then smallest number such that every partial product + 1 is a distinct square.

3, 5, 8, 3, 14, 40, 1270, 15874, 251984126, 28673777890680889, 2806729404119595479093401735, 15973219322678152520589944038429546981629762353084607

Offset

1,1

Links

Table of n, a(n) for n=1..12.

Example

3 + 1 = 4, 3*5 + 1 = 16, 3*5*8 + 1 = 121 etc. are squares.

Mathematica

p = 1; Do[k = 2; While[ !IntegerQ[Sqrt[p*k + 1]], k++ ]; Print[k]; p *= k, {n, 1, 9}] (* Ryan Propper *)

Crossrefs

Cf. A068559, A087335.

Sequence in context: A019830 A259238 A094355 * A175628 A387574 A119360

Adjacent sequences: A087331 A087332 A087333 * A087335 A087336 A087337

Keyword

nonn

Author

Amarnath Murthy, Sep 06 2003, May 22 2004

Extensions

Edited by Don Reble, Sep 12 2003

Entry revised by N. J. A. Sloane, Aug 29 2006

Status

approved