A120293 Absolute value of numerator of determinant of n X n matrix with M(i,j) = (i+1)/(i+2) if i=j otherwise 1.

2, 1, 11, 17, 1, 1, 41, 17, 31, 37, 29, 101, 29, 1, 149, 167, 31, 103, 227, 83, 1, 37, 107, 347, 1, 67, 431, 461, 41, 131, 557, 197, 313, 331, 233, 67, 97, 1, 857, 1, 157, 1, 1031, 359, 281, 293, 1, 1, 661, 229, 1427, 1481, 1, 199, 97, 569, 883, 83, 1, 1949, 503, 173

Offset: 1

Author

Alexander Adamchuk, Jul 08 2006

Keywords

• frac
• nonn

Comments

Some a(n) are equal to 1 (n=2,5,6,14,21,25,38,40,42,47,48,53,59,69,70..). All other a(n) are primes that belong to A038907 (33 is a square mod p).

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..300

Crossrefs

Cf. A118679, A038907.

Programs

Mathematica

Abs[Numerator[Table[Det[DiagonalMatrix[Table[(i+1)/(i+2)-1,{i,1,n}]]+1],{n,1,70}]]]

Formula

a(n) = Abs[numerator[Det[DiagonalMatrix[Table[(i+1)/(i+2)-1,{i,1,n}]]+1]]].