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%I #12 Dec 21 2018 22:06:53
%S 0,1,19,280,3691,45739,544870,6315481,71743159,802527760,8868438271,
%T 97038694279,1053164192950,11351825985061,121644911602099,
%U 1296970638284440,13767539948978851,145580595285369619,1534133217109136230,16117424311550552641
%N Number of decimal strings of length n that contain a specific string xx (where x is a single digit).
%C See A322054 for the number that do not contain the specified string.
%F G.f. = x^2/((1-10*x)*(1-9*x-9*x^2)).
%e Suppose the desired string is 00. At length 2 that is the only possibility. At length 3 there are 19 strings that contain it: 000, 00d, and d00, where d is any nonzero digit.
%Y Cf. A322052, A004189, A322054.
%Y Suggested by A322628.
%K nonn,base
%O 1,3
%A _N. J. A. Sloane_, Dec 21 2018