USING: kernel sequences math locals ;

: mid-depth-clone ( seq -- seq' )
    [ clone ] map ;

:: [recur-quot] ( vals quot -- quot' )
    [
        vals first2 quot call
        vals second 0 vals set-nth 1 vals set-nth
    ] ; inline

! quots should be ( a[n-1] a[n] -- a[n+1] )
:: 2-recurrence ( n start-vals quots -- end-vals )
    start-vals mid-depth-clone
    dup quots [ [recur-quot] ] 2map [ n ] dip
    [ over 0 > ]
    [ [ 1 - ] [ dup [ call ] each ] bi* ] while 2drop ; inline

! Use like
!    10 { { 1 1 } } { [ + ] } 2-recurrence .