Sequence a(n) = 2 + 3*A001519(n+1) appearing in a certain four circle touching problem together with A246639.

A246638

Sequence a(n) = 2 + 3*A001519(n+1) appearing in a certain four circle touching problem together with A246639.

Terms

    a(0) =5a(1) =8a(2) =17a(3) =41a(4) =104a(5) =269a(6) =701a(7) =1832a(8) =4793a(9) =12545a(10) =32840a(11) =85973a(12) =225077a(13) =589256a(14) =1542689a(15) =4038809a(16) =10573736a(17) =27682397a(18) =72473453a(19) =189737960a(20) =496740425a(21) =1300483313a(22) =3404709512a(23) =8913645221a(24) =23336226149a(25) =61095033224a(26) =159948873521a(27) =418751587337

External references