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 A289544 #48 Dec 05 2023 16:12:24 %S A289544 2467891035,2497861035,2647891053,2697841053,2847691053,2867491035, %T A289544 2897461035,2897641053,3247651089,3257641089,3427561098,3467521098, %U A289544 3478591206,3498571206,3527461098,3567421098,3578491206,3598471206,3647251089,3657241089,4236751098,4256731098 %N A289544 Pandigital numbers (each digit 0-9 used exactly once) where the first 3 digits plus the next 3 digits equals the last 4 digits. %C A289544 Leading zeros in the last four digits are not included, else 1246590783, with 124 + 659 = 783 would be the first term. %H A289544 Jonathan Schwartz, <a href="/A289544/b289544.txt">Table of n, a(n) for n = 1..96</a> %H A289544 David A. Corneth, <a href="/A289544/a289544.gp.txt">PARI program</a> %e A289544 2467891035 is in the sequence as 246|789|1035: 246 + 789 = 1035 and each digit (0-9) is used exactly once. %t A289544 FromDigits /@ Select[Permutations[Range[0, 9]], And[#1 + #2 == #3, #3 >= 1000] & @@ Map[FromDigits, {Take[#, 3], #[[4 ;; 6]], Take[#, -4]}] &] (* _Michael De Vlieger_, Aug 02 2018 *) %o A289544 (Python) %o A289544 from itertools import permutations %o A289544 def t2i(t): return int("".join(map(str, t))) %o A289544 alst = [t2i(p) for p in permutations(range(10)) if p[6] != 0 and t2i(p[:3]) + t2i(p[3:6]) == t2i(p[6:])] %o A289544 print(alst) # _Michael S. Branicky_, May 30 2022 %Y A289544 Cf. A050278, A289552, A286846. %K A289544 nonn,base,fini,full %O A289544 1,1 %A A289544 _Jonathan Schwartz_, Aug 02 2017