140017356880domain: NAppears in sequencesa(n) = A027941(n) + A027941(n+6).at n=21A153466Linear recurrence with a(n) = 3a(n-1) - a(n-2) + 2 = 4a(n-1) - 4a(n-2) + a(n-3). Full sequence for A153466.at n=24A153819