A003126 Value of an urn with n balls of type -1 and n+1 balls of type +1. (Formerly M3501)

1, 4, 15, 58, 226, 882, 3457, 13606, 53683, 212090, 838484, 3319596, 13159676, 52220801, 207374051, 823906473, 3274464556, 13019414133, 51790661881, 206112818880, 820583696869, 3267935428368, 13017497498243, 51863262314021

Offset

1,2

References

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

Table of n, a(n) for n=1..24.

W. M. Boyce, On a simple optimal stopping problem, Discr. Math., 5 (1973), 297-312.

Formula

a(n) = B(n, n + 1) where B(n, m) is defined in A003125.

Crossrefs

Cf. A003125.

Sequence in context: A307570 A164589 A017950 * A160156 A102052 A128714

Adjacent sequences: A003123 A003124 A003125 * A003127 A003128 A003129

Keyword

nonn

Author

N. J. A. Sloane

Extensions

More terms and title clarified by Sean A. Irvine, Feb 02 2015

Status

approved