A096423 a(1)=a(2)=1, a(n) = (a(n-1)+1)*(a(n-2)+1) for n > 2.

1, 1, 4, 10, 55, 616, 34552, 21319201, 736642386706, 15704627843968647814, 11568694537326272321321120595205, 181682042349262169758803442669575561298555791374890

Offset

1,3

Comments

The terms have an interesting factorization pattern, often sharing factors.

The next term (a(13)) has 82 digits. - Harvey P. Dale, Feb 27 2015

Links

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

Mathematica

RecurrenceTable[{a[1]==a[2]==1, a[n]==(a[n-1]+1)(a[n-2]+1)}, a, {n, 15}] (* Harvey P. Dale, Feb 27 2015 *)

Crossrefs

Sequence in context: A192444 A197902 A276123 * A276130 A263044 A013589

Adjacent sequences: A096420 A096421 A096422 * A096424 A096425 A096426

Keyword

nonn

Author

Gerald McGarvey, Aug 08 2004

Status

approved