A081952 Smallest Fibonacci number which is one more than the product of n distinct numbers > 1.

3, 13, 55, 1597, 17711, 1346269, 165580141, 2971215073, 7778742049, 308061521170129, 308061521170129, 135301852344706746049, 3311648143516982017180081, 1983924214061919432247806074196061

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..56

Formula

a(n) = A000045(A119249(n)). - R. J. Mathar, Feb 06 2010

Example

a(3) = 2*3*9 + 1 = 55;
a(4) = 3*4*7*19 + 1 = 1597;
a(5) = 2*5*7*11*23 + 1 = 17711;
a(6) = 3*4*7*11*31*47 + 1 = 1346269;
a(7) = 3*4*5*11*29*41*211 + 1 = 165580141;
a(8) = 2*3*6*7*8*23*139*461 + 1 = 2971215073.

Mathematica

f[n_, m_, 0] := n == 1; f[n_, m_, d_] := (b = False; l = Select[Divisors[n], #>=m&]; For[i = 1, i <= Length[l], i++, k = l[[i]]; If[f[n / k, k + 1, d - 1], b = True; Break[]]]; b); Do[x = 3; While[ !f[Fibonacci[x] - 1, 2, y], x++ ]; Print[Fibonacci[x]], {y, 1, 50}] (* Ryan Propper, Jul 22 2006 *)

Crossrefs

Subset of A000045.

Cf. A000071, A081953, A119249.

Sequence in context: A151219 A006225 A100588 * A234645 A010920 A010903

Adjacent sequences: A081949 A081950 A081951 * A081953 A081954 A081955

Keyword

nonn

Author

Amarnath Murthy, Apr 02 2003

Extensions

More terms from R. J. Mathar, Apr 13 2006

More terms from Ryan Propper, Jul 22 2006

Edited by Jon E. Schoenfield, Nov 18 2018

Status

approved