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A147818
Period 4: repeat [5, 9, 9, 5].
1
5, 9, 9, 5, 5, 9, 9, 5, 5, 9, 9, 5, 5, 9, 9, 5, 5, 9, 9, 5, 5, 9, 9, 5, 5, 9, 9, 5, 5, 9, 9, 5, 5, 9, 9, 5, 5, 9, 9, 5, 5, 9, 9, 5, 5, 9, 9, 5, 5, 9, 9, 5, 5, 9, 9, 5, 5, 9, 9, 5, 5, 9, 9, 5, 5, 9, 9, 5, 5, 9, 9, 5, 5, 9, 9, 5, 5, 9, 9, 5, 5, 9, 9, 5, 5, 9, 9, 5, 5, 9, 9, 5, 5, 9, 9, 5, 5, 9, 9, 5, 5, 9, 9, 5, 5
OFFSET
1,1
COMMENTS
Last digit of the number whose binary representation is the concatenation of n 1's, 2n-1 0's and n 1's.
a(n) is the final digit of A147539(n).
FORMULA
a(n+1) = 7-2*cos(Pi*n/2)+2*sin(Pi*n/2). - R. J. Mathar, Oct 08 2011
a(n) = a(n-1)-a(n-2)+a(n-3) for n>3. G.f.: x*(5*x^2+4*x+5)/((1-x)*(x^2+1)). [Colin Barker, Nov 04 2012]
a(n) = a(n-4) for n>4. - Wesley Ivan Hurt, Jul 09 2016
MAPLE
A010879 := proc(n) n mod 10; end:
A147539 := proc(n) 2^n-1+2^(4*n-1)-2^(3*n-1); end:
A147818 := proc(n) A010879(A147539(n)); end: # R. J. Mathar, Jan 22 2009
seq(op([5, 9, 9, 5]), n=1..40); # Wesley Ivan Hurt, Jul 09 2016
MATHEMATICA
PadRight[{}, 100, {5, 9, 9, 5}] (* Wesley Ivan Hurt, Jul 09 2016 *)
PROG
(Magma) &cat [[5, 9, 9, 5]^^30]; // Wesley Ivan Hurt, Jul 09 2016
CROSSREFS
Sequence in context: A085566 A076390 A321632 * A345739 A055199 A147777
KEYWORD
base,easy,nonn
AUTHOR
Omar E. Pol, Nov 14 2008, Jan 25 2009
EXTENSIONS
More terms from R. J. Mathar, Jan 22 2009
STATUS
approved