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

1,1

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

Formula

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

Mathematica

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

Crossrefs

Cf. A118679, A038907.

Sequence in context: A055459 A080958 A138351 * A063624 A101851 A300455

Adjacent sequences: A120290 A120291 A120292 * A120294 A120295 A120296

Keyword

frac,nonn

Author

Alexander Adamchuk, Jul 08 2006

Status

approved