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%I #10 Oct 10 2019 00:48:55
%S 0,0,0,0,0,2,6,8,1,7,2,4,3,1,3,2,4,5,1,6,4,2,5,1,2,0,2,6,8,2,6,0,6,8,
%T 8,0,6,2,6,2,8,0,0,2,6,8,1,1,5,7,1,7,1,1,5,1,7,1,5,1,1,1,4,2,0,4,2,4,
%U 4,6,0,6,4,0,6,0,6,4,3,5,5,3,3,1,5,1,5,3,3,1,3,5,3,3,5,2,4,4,2,4,2,2,2,4,4
%N |First digit - last digit| for n-th prime.
%F a(n) = A040163(A000040(n)). - _Michel Marcus_, Sep 27 2013
%o (PARI) a(n) = my(pn = prime(n), digs = digits(pn)); abs(digs[1] - digs[#digs]); \\ _Michel Marcus_, Sep 27 2013
%Y Cf. A000040, A040163.
%K nonn,base,easy
%O 1,6
%A _Felice Russo_
%E Extended (and corrected) by _Patrick De Geest_, Jun 15 1999