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A073094 Final digit of C(2k,k) when not equal to zero. 1
2, 6, 2, 4, 2, 6, 2, 6, 2, 4, 2, 4, 8, 4, 2, 4, 2, 6, 2, 6, 2, 4, 2, 6, 2, 6, 2, 4, 2, 4, 8, 4, 2, 4, 2, 4, 8, 4, 8, 6, 8, 4, 8, 4, 2, 4, 2, 4, 8, 4, 2, 4, 2, 6, 2, 6, 2, 4, 2, 6, 2, 6, 2, 4, 2, 4, 8, 4, 2, 4, 2, 6, 2, 6, 2, 4, 2, 6, 2, 6, 2, 4, 2, 4, 8, 4, 2, 4, 2, 4, 8, 4, 8, 6, 8, 4, 8, 4, 2, 4, 2, 4, 8, 4, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Sequence contains 2,4,6,8, only.
LINKS
FORMULA
a(n) = C(2*A037453(n), A037453) reduced modulo 10.
MAPLE
f:= proc(n) local L, r;
L:= convert(n, base, 3);
r:= 2 &^ numboccur(1, L) mod 5;
r + 5*(r mod 2)
end proc:
map(f, [$1..200]); # Robert Israel, Jun 11 2018
MATHEMATICA
Mod[#, 10]&/@Table[Binomial[2n, n], {n, 800}]/.(0->Nothing) (* Harvey P. Dale, Apr 14 2018 *)
CROSSREFS
Sequence in context: A265993 A115009 A151944 * A194953 A057606 A021385
KEYWORD
easy,nonn,base
AUTHOR
Benoit Cloitre, Aug 18 2002
STATUS
approved

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Last modified April 22 01:34 EDT 2024. Contains 371887 sequences. (Running on oeis4.)