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 A284815 Least number k such that k mod (2, 3, 4, ... , n+1) = (d_n, d_n-1, ..., d_1), where d_1 , d_2, …, d_n are the digits of k, with MSD(k) = d_1 and LSD(k) = d_n. 0 if such a number does not exist. 2
 1, 10, 0, 1101, 11311, 340210, 4620020, 12040210, 151651121, 1135531101, 0, 894105331101, 0, 15379177511311, 0 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS EXAMPLE a(7) = 4620020 because: 4620020 mod 2 = 0, 4620020 mod 3 = 2, 4620020 mod 4 = 0, 4620020 mod 5 = 0, 4620020 mod 6 = 2, 4620020 mod 7 = 6, 4620020 mod 8 = 4. MAPLE P:=proc(q) local a, d, j, k, n, ok; for k from 1 to q do d:=0; for n from 10^(k-1) to 10^k-1 do ok:=1; a:=n; for j from 1 to ilog10(n)+1 do if (a mod 10)<>n mod (j+1) then ok:=0; break; else a:=trunc(a/10); fi; od; if ok=1 then print(n); d:=1; break; fi; od; if n=10^k and d=0 then print(0); fi; od; end: P(20); CROSSREFS Sequence in context: A286018 A286646 A104013 * A286116 A286082 A286730 Adjacent sequences:  A284812 A284813 A284814 * A284816 A284817 A284818 KEYWORD nonn,base,hard,more AUTHOR Paolo P. Lava, Apr 10 2017 EXTENSIONS a(11)-a(15) from Giovanni Resta, Apr 10 2017 STATUS approved

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Last modified May 15 20:23 EDT 2021. Contains 343920 sequences. (Running on oeis4.)