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A062321
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a(1) = 1; a(n) = gcd {n*(n+1), a(n-1) * (a(n-1) + 1)} for n > 1.
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1
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1, 2, 6, 2, 6, 42, 14, 6, 6, 2, 6, 6, 14, 210, 30, 2, 6, 6, 2, 6, 42, 2, 6, 6, 2, 6, 42, 14, 30, 930, 62, 6, 6, 14, 210, 6, 2, 6, 6, 2, 6, 42, 86, 6, 6, 2, 6, 42, 14, 30, 6, 2, 6, 6, 14, 42, 6, 2, 6, 6, 2, 6, 42, 2, 6, 6, 2, 6, 42, 14, 6, 6, 2, 6, 6, 14, 42, 6, 2, 6, 6, 2, 6, 42, 86, 7482
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OFFSET
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1,2
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LINKS
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EXAMPLE
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a(31) = gcd(31 * 32, a(30) * (a(30) + 1)) = gcd(31*32, 930*931) = 62
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MATHEMATICA
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RecurrenceTable[{a[1]==1, a[n]==GCD[n(n+1), a[n-1](a[n-1]+1)]}, a, {n, 90}] (* Harvey P. Dale, Dec 21 2011 *)
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PROG
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(PARI) { for (n=1, 1000, if (n>1, a=gcd(n*(n + 1), a*(a + 1)), a=1); write("b062321.txt", n, " ", a) ) } \\ Harry J. Smith, Aug 04 2009
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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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