a(n) = ((5 + 2*sqrt(2))*(2 + sqrt(2))^n + (5 - 2*sqrt(2))*(2 - sqrt(2))^n)/2.
A163608
a(n) = ((5 + 2*sqrt(2))*(2 + sqrt(2))^n + (5 - 2*sqrt(2))*(2 - sqrt(2))^n)/2.
Terms
- a(0) =5a(1) =14a(2) =46a(3) =156a(4) =532a(5) =1816a(6) =6200a(7) =21168a(8) =72272a(9) =246752a(10) =842464a(11) =2876352a(12) =9820480a(13) =33529216a(14) =114475904a(15) =390845184a(16) =1334428928a(17) =4556025344a(18) =15555243520a(19) =53108923392a(20) =181325206528a(21) =619082979328
External references
- oeis: A163608