A238546 Number of partitions p of n such that floor(n/2) is not a part of p.
1, 1, 1, 3, 4, 8, 10, 17, 23, 35, 45, 66, 86, 120, 154, 209, 267, 355, 448, 585, 736, 946, 1178, 1498, 1857, 2335, 2875, 3583, 4389, 5428, 6611, 8118, 9846, 12013, 14498, 17592, 21147, 25525, 30558, 36711, 43791, 52382, 62259, 74173, 87879, 104303, 123179
Offset: 1
Examples
a(6) counts all the 11 partitions of 6 except 33, 321, 3111.
Links
- Giovanni Resta, Table of n, a(n) for n = 1..500
Crossrefs
Cf. A119620.
Programs
-
Mathematica
Table[Count[IntegerPartitions[n], p_ /; !MemberQ[p, Floor[n/2]]], {n, 50}]
Formula
a(n) = p(n) - p(ceiling(n/2)) = A000041(n) - A000041(ceiling(n/2)), for n>1. - Giovanni Resta, Mar 02 2014