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A122961
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Alternately form product and sum of all previous terms.
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0
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1, 1, 1, 3, 3, 9, 81, 99, 649539, 649737, 274124633198656977, 274124633199956451, 20598907656583661830059012023854018733151994905840579, 20598907656583661830059012023854019281401261305753481
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,4
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COMMENTS
| Note that definition does not make a(1) a special case; it is the empty product, which is 1. If we started with addition, the sequence would be all zeros.
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FORMULA
| a(1) = a(2) = 1. For n > 1, a(2n-1) = a(2n-3)^2 * a(2n-2), a(2n) = 2 * a(2n-2) + a(2n-1).
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CROSSREFS
| Cf. A039941, A000004.
Sequence in context: A038080 A190960 A115564 * A165421 A100731 A072004
Adjacent sequences: A122958 A122959 A122960 * A122962 A122963 A122964
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KEYWORD
| nonn
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AUTHOR
| Franklin T. Adams-Watters (FrankTAW(AT)Netscape.net), Oct 26 2006
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