22361430

Appears in sequences

• M(M-1)/3, where M is Mersenne prime A000668(n).at n=4A139225
• Second elementary symmetric function of the first n terms of (1,2,4,8,...).at n=11A203241
• Number of set partitions of [n] into exactly four blocks such that all odd elements are in blocks with an odd index and all even elements are in blocks with an even index.at n=23A274868