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A018907
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Define the sequence S(a_0,a_1) by a_{n+2} is the least integer such that a_{n+2}/a_{n+1} > a_{n+1}/a_n for n >= 0. This is S(2,7).
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1
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2, 7, 25, 90, 325, 1174, 4241, 15321, 55349, 199956, 722370, 2609667, 9427803, 34059315, 123044249, 444515318, 1605876501, 5801463374, 20958633656, 75716124779, 273535557978, 988187148996, 3569970385786, 12897039359739, 46592438107869, 168321986797406
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OFFSET
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0,1
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LINKS
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MAPLE
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a:= proc(n) option remember; `if`(n<2, [2, 7][n+1],
1 +floor(a(n-1)^2/a(n-2)))
end:
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MATHEMATICA
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a[n_] := a[n] = Switch[n, 0, 2, 1, 7, _, 1 + Floor[a[n-1]^2/a[n-2]]];
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PROG
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(PARI) S(a0, a1, maxn) = a=vector(maxn); a[1]=a0; a[2]=a1; for(n=3, maxn, a[n]=a[n-1]^2\a[n-2]+1); a
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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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