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A178874
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Partial sums of round(5^n/8).
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1
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0, 1, 4, 20, 98, 489, 2442, 12208, 61036, 305177, 1525880, 7629396, 38146974, 190734865, 953674318, 4768371584, 23841857912, 119209289553, 596046447756, 2980232238772, 14901161193850, 74505805969241, 372529029846194
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OFFSET
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0,3
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LINKS
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FORMULA
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a(n) = round((5*5^n + 4*n - 1)/32) = round((5*5^n + 4*n - 5)/32).
a(n) = floor((5*5^n + 4*n + 3)/32).
a(n) = ceiling((5*5^n + 4*n - 5)/32).
a(n) = a(n-2) + (3*5^(n-1) + 1)/4 , n > 1.
a(n) = 6*a(n-1) - 4*a(n-2) - 6*a(n-3) + 5*a(n-4), n > 3.
G.f.: (2*x^2-x)/((x+1)*(5*x-1)*(x-1)^2).
a(n) = (5^(n+1) + 4*n - 4*(-1)^n - 1)/32. - Bruno Berselli, Jan 12 2011
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EXAMPLE
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a(2) = 0 + 1 + 3 = 4.
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MAPLE
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A178874 := proc(n) add( round(5^i/8), i=0..n) ; end proc:
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MATHEMATICA
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PROG
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CROSSREFS
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KEYWORD
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nonn,less
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AUTHOR
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STATUS
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approved
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