Number of zero-sum -3..3 arrays of n elements with first through third differences also in -3..3.

A202506

Number of zero-sum -3..3 arrays of n elements with first through third differences also in -3..3.

Terms

    a(0) =1a(1) =3a(2) =15a(3) =29a(4) =95a(5) =255a(6) =747a(7) =2215a(8) =6649a(9) =19967a(10) =60145a(11) =182003a(12) =554625a(13) =1691547a(14) =5175093a(15) =15875649a(16) =48789933a(17) =150258301a(18) =463501341a(19) =1431832723a(20) =4429155217a(21) =13716674493a(22) =42524970155a(23) =131966196475a(24) =409893633219

External references