236631domain: NAppears in sequencesFibonacci sequence beginning 1, 21.at n=21A022391Numerators of convergents of the continued fraction with the n+1 partial quotients: [1;1,1,...(n 1's)...,1,n+1], starting with [1], [1;2], [1;1,3], [1;1,1,4], ...at n=20A088209