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 A080480 #13 Jan 23 2021 09:50:30
%S A080480 1,32,654,98710,5432111111,987622111110,87654322222222,
%T A080480 9654333333332210,987544444443333210,98765555555444443210,
%U A080480 9876666666665555543210,988777777777776666543210,99998888888888877654321100,9999999998765544332211111110000000
%N A080480 Largest number formed by using all the digits (with multiplicity) of next n numbers.
%H A080480 Harvey P. Dale, <a href="/A080480/b080480.txt">Table of n, a(n) for n = 1..200</a>
%e A080480 a(4) = 98710 formed by using digits of 7,8,9 and 10.
%t A080480 FromDigits[Sort[Flatten[IntegerDigits/@#],Greater]]&/@Table[ Reverse[ Range[ (n(n+1))/2+1,((n+1)(n+2))/2]],{n,0,15}] (* _Harvey P. Dale_, May 13 2017 *)
%o A080480 (Python)
%o A080480 def a(n):
%o A080480 s = "".join(sorted("".join(map(str, range((n-1)*n//2+1, n*(n+1)//2+1)))))
%o A080480 return int("".join(sorted(s, reverse=True)))
%o A080480 print([a(n) for n in range(1, 15)]) # _Michael S. Branicky_, Jan 23 2021
%Y A080480 Cf. A053067 (next n concatenated), A076068 (smallest without zeros), A080479 (smallest).
%K A080480 base,easy,nonn
%O A080480 1,2
%A A080480 _Amarnath Murthy_, Mar 11 2003
%E A080480 More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Apr 19 2003
%E A080480 More terms from _Harvey P. Dale_, May 13 2017