A073094 Final digit of C(2k,k) when not equal to zero.

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

Offset

1,1

Comments

Sequence contains 2,4,6,8, only.

Links

Robert Israel, Table of n, a(n) for n = 1..10000

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

Adjacent sequences: A073091 A073092 A073093 * A073095 A073096 A073097

Keyword

easy,nonn,base

Author

Benoit Cloitre, Aug 18 2002

Status

approved