This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A083449 #24 Nov 22 2020 21:15:42
%S A083449 0,1,22,343,4664,58985,713306,8367627,96021948,-150891621,
%T A083449 -13731137410,-260644605199,86159119727012,19839246664059223,
%U A083449 3106259112208391434,422859356777752723645,53509280234443297055856,6473262479112108841388067,759559693477989774385720278
%N A083449 a(n) = A019566(n)/9, where A019566(n) = concat(n,...,1) - concat(1,...,n).
%C A083449 Are there any palindromes > 58985?
%C A083449 This sequence also gives the number of occurrences of any digit d > n (thus n < 9) in the list of all numbers from 1 to concatenation(1,...,n) = A007908(n) = A014824(n) = sum_{i=1..n} i*10^(n-i). See A277849, A061217, A277830 etc. - _M. F. Hasler_, Nov 01 2016, edited Nov 07 2020
%F A083449 For n < 10, a(n) = ceiling((9*n-11)*(10^n+1)/729). - _M. F. Hasler_, Nov 07 2020
%p A083449 a:= n-> (parse(cat((n+1-i)$i=1..n))-parse(cat($1..n)))/9:
%p A083449 seq(a(n), n=1..20); # _Alois P. Heinz_, Nov 09 2020
%t A083449 Array[(FromDigits@ Apply[Join, Reverse@ #] - FromDigits@ Apply[Join, #])/9 &@ Map[IntegerDigits, Range[#]] &, 19] (* _Michael De Vlieger_, Nov 12 2020 *)
%o A083449 (PARI) apply( {A083449(n)=A019566(n)\9}, [1..20]) \\ - _M. F. Hasler_, Nov 07 2020
%Y A083449 Cf. A061217.
%K A083449 base,easy,sign
%O A083449 1,3
%A A083449 _Amarnath Murthy_ and Meenakshi Srikanth (menakan_s(AT)yahoo.com), May 01 2003
%E A083449 More terms from _David Wasserman_, Nov 09 2004