Composite-then-prime recurrence; a(2n) = a(2n-1)-th composite and a(2n+1) = a(2n)-th prime and a(1) = 1.

A064961

Composite-then-prime recurrence; a(2n) = a(2n-1)-th composite and a(2n+1) = a(2n)-th prime and a(1) = 1.

Terms

    a(0) =1a(1) =4a(2) =7a(3) =14a(4) =43a(5) =62a(6) =293a(7) =366a(8) =2473a(9) =2892a(10) =26317a(11) =29522a(12) =344249a(13) =376259a(14) =5429539a(15) =5831545a(16) =101291779a(17) =107457490a(18) =2198218819a(19) =2310909505a(20) =54720307351a(21) =57128530327

External references