a(n) is the number whose base-4 digits are 1 followed by the first n-1 terms of the periodic sequence with initial period 3,2,0.

A378502

a(n) is the number whose base-4 digits are 1 followed by the first n-1 terms of the periodic sequence with initial period 3,2,0.

Terms

    a(0) =1a(1) =7a(2) =30a(3) =120a(4) =483a(5) =1934a(6) =7736a(7) =30947a(8) =123790a(9) =495160a(10) =1980643a(11) =7922574a(12) =31690296a(13) =126761187a(14) =507044750a(15) =2028179000a(16) =8112716003a(17) =32450864014a(18) =129803456056a(19) =519213824227

External references