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A061419
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a(n) = ceiling(a(n-1)*3/2) with a(1) = 1.
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31
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1, 2, 3, 5, 8, 12, 18, 27, 41, 62, 93, 140, 210, 315, 473, 710, 1065, 1598, 2397, 3596, 5394, 8091, 12137, 18206, 27309, 40964, 61446, 92169, 138254, 207381, 311072, 466608, 699912, 1049868, 1574802, 2362203, 3543305, 5314958, 7972437, 11958656
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OFFSET
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1,2
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COMMENTS
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It appears that this sequence is the (L)-sieve transform of {3,6,9,12,...,3n,...} = A008585. (See A152009 for the definition of the (L)-sieve transform.) - John W. Layman, Jan 06 2009
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LINKS
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FORMULA
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a(n) = A061418(n) - 1 = floor(K*(3/2)^n) where K = 1.08151366859...
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EXAMPLE
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a(6) = ceiling(8*3/2) = 12.
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MAPLE
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a:=proc(n) option remember: if n=1 then 1 else ceil(procname(n-1)*3/2) fi; end; seq(a(n), n=1..40); # Muniru A Asiru, Jun 07 2018
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MATHEMATICA
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PROG
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(Magma) [ n eq 1 select 1 else Ceiling(Self(n-1)*3/2): n in [1..40] ]; // Klaus Brockhaus, Nov 14 2008
(PARI) { a=2/3; for (n=1, 500, write("b061419.txt", n, " ", a=ceil(a*3/2)) ) } \\ Harry J. Smith, Jul 22 2009
(Python)
from itertools import islice
def A061419_gen(): # generator of terms
a = 2
while True:
yield a-1
a += a>>1
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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