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A235500
Numbers k such that k and all its prefixes are a multiple of the difference between their length and their last digit.
1
0, 2, 20, 21, 23, 24, 202, 204, 210, 212, 214, 216, 232, 234, 240, 242, 244, 246, 2020, 2022, 2023, 2025, 2026, 2028, 2040, 2042, 2043, 2045, 2046, 2048, 2100, 2102, 2103, 2105, 2106, 2108, 2120, 2121, 2122, 2123, 2125, 2126, 2127, 2128, 2140, 2142, 2143
OFFSET
1,2
COMMENTS
The sequence has 1117896 terms, all beginning with 2, apart 0. The largest term is 2160088425040528890600488466.
LINKS
EXAMPLE
2128 is a term because 2 is divisible by (1-2), 21 by (2-1), 212 by (3-1) and 2128 by (4-8).
MATHEMATICA
r[v_, nd_] := Block[{w=10*v, d=nd+1}, Do[ If[w < 10^4 && i != d && Mod[w, d-i] == 0, Sow@ w; r[w, d]]; w++, {i, 0, 9}]]; Union[{0, 2}, Reap[r[2, 1]][[2, 1]]] (* terms < 10^4 *)
CROSSREFS
Cf. A144688.
Sequence in context: A217394 A072998 A024629 * A319953 A111193 A136906
KEYWORD
nonn,base,fini
AUTHOR
Giovanni Resta, Jan 11 2014
STATUS
approved