A198959 a(1) = 2, a(n+1) = a(n)^2 - n.

2, 3, 7, 46, 2112, 4460539, 19896408170515, 395867058087736049315365218, 156710727679038987453730700439845485538142584724187516

Offset: 1

Author

Franklin T. Adams-Watters, Nov 01 2011

Keywords

• nonn
• easy

Comments

The next term -- a(10) -- has 107 digits. - Harvey P. Dale, Jun 22 2022

Links

• MathOverflow, Asymptotic behavior of the sequence u(n) = u(n-1)^2 - n

Crossrefs

Cf. A086051.

Programs

Mathematica

RecurrenceTable[{a[1]==2,a[n+1]==a[n]^2-n},a,{n,10}] (* Harvey P. Dale, Jun 22 2022 *)

PARI

vector(10,k,t=if(k==1,2,t^2-(k-1)))