a(n) is the least practical number A005153(k) such that A005153(k+1) - A005153(k) = 2*n, or -1 if no such number exists.

A364707

a(n) is the least practical number A005153(k) such that A005153(k+1) - A005153(k) = 2*n, or -1 if no such number exists.

Terms

    a(0) =2a(1) =8a(2) =42a(3) =112a(4) =368a(5) =180a(6) =1806a(7) =936a(8) =840a(9) =1600a(10) =14168a(11) =6216a(12) =25120a(13) =6272a(14) =16770a(15) =52668a(16) =83720a(17) =24240a(18) =103840a(19) =29440a(20) =35910a(21) =184140a(22) =278334a(23) =197912a(24) =282150a(25) =313040a(26) =266112a(27) =337840a(28) =1438722a(29) =468540

External references