a(n) = 7*a(n-1) + (-1)^n * binomial(2,2-n) with a(-1)=0.
A055270
a(n) = 7*a(n-1) + (-1)^n * binomial(2,2-n) with a(-1)=0.
Terms
- a(0) =1a(1) =5a(2) =36a(3) =252a(4) =1764a(5) =12348a(6) =86436a(7) =605052a(8) =4235364a(9) =29647548a(10) =207532836a(11) =1452729852a(12) =10169108964a(13) =71183762748a(14) =498286339236
External references
- oeis: A055270