a(n) = 7*a(n-1) - 14*a(n-2) + 7*a(n-3) with a(1)=7, a(2)=21, a(3)=70.
A215494
a(n) = 7*a(n-1) - 14*a(n-2) + 7*a(n-3) with a(1)=7, a(2)=21, a(3)=70.
Terms
- a(0) =7a(1) =21a(2) =70a(3) =245a(4) =882a(5) =3234a(6) =12005a(7) =44933a(8) =169099a(9) =638666a(10) =2417807a(11) =9167018a(12) =34790490a(13) =132119827a(14) =501941055a(15) =1907443237a(16) =7249766678a(17) =27557748813a(18) =104759610858a(19) =398257159370
External references
- oeis: A215494