Number of -3..3 arrays of n elements with first, second and third differences also in -3..3.

A202119

Number of -3..3 arrays of n elements with first, second and third differences also in -3..3.

Terms

    a(0) =7a(1) =37a(2) =153a(3) =475a(4) =1509a(5) =4763a(6) =15101a(7) =47889a(8) =151833a(9) =481519a(10) =1527001a(11) =4842421a(12) =15356565a(13) =48699233a(14) =154436377a(15) =489754155a(16) =1553125143a(17) =4925322519a(18) =15619350977a(19) =49532617623a(20) =157079520865a(21) =498135926335

External references