Numbers n that have an equal number of even and odd values of A001221(k) for 1 <= k <= n.

Terms

a(0) =2a(1) =40a(2) =46a(3) =48a(4) =50a(5) =7960a(6) =7962a(7) =7984a(8) =7986a(9) =8808a(10) =8810a(11) =8812a(12) =8816a(13) =8822a(14) =8824a(15) =8826a(16) =8828a(17) =8830a(18) =8836a(19) =8844a(20) =8846a(21) =8848a(22) =8850a(23) =8854a(24) =8856a(25) =8858a(26) =8860a(27) =8862a(28) =8864a(29) =8866