A131107 Rectangular array read by antidiagonals: k objects are each put into one of n boxes, independently with equal probability. a(n, k) is the expected number of boxes with exactly one object (n, k >= 1). Sequence gives the denominators.

1, 1, 1, 1, 1, 1, 1, 3, 4, 1, 1, 2, 3, 2, 1, 1, 5, 16, 27, 16, 1, 1, 3, 25, 16, 81, 16, 1, 1, 7, 12, 125, 256, 81, 64, 1, 1, 4, 49, 54, 125, 512, 729, 16, 1, 1, 9, 64, 343, 1296, 3125, 4096, 2187, 256, 1, 1, 5, 27, 128, 2401, 1296, 15625, 2048, 729, 256, 1, 1, 11, 100, 729, 4096

Offset

1,8

Links

Table of n, a(n) for n=1..71.

Crossrefs

Cf. A131106 gives the numerators.

Sequence in context: A137925 A171528 A299924 * A046547 A016453 A238550

Adjacent sequences: A131104 A131105 A131106 * A131108 A131109 A131110

Keyword

easy,frac,nonn,tabl

Author

David Wasserman, Jun 15 2007

Status

approved