a(n) = (8*5^n + 5*3^(n+1) - 5*2^n)/3.

A147543

a(n) = (8*5^n + 5*3^(n+1) - 5*2^n)/3.

Terms

    a(0) =6a(1) =25a(2) =105a(3) =455a(4) =2045a(5) =9495a(6) =45205a(7) =219055a(8) =1074045a(9) =5305895a(10) =26335205a(11) =131090655a(12) =653692045a(13) =3263166295a(14) =16299929205a(15) =81451898255a(16) =407116166045

External references