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A039941
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Alternately add and multiply.
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6
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0, 1, 1, 1, 2, 2, 4, 8, 12, 96, 108, 10368, 10476, 108615168, 108625644, 11798392572168192, 11798392680793836, 139202068568601556987554268864512, 139202068568601568785946949658348
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,5
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LINKS
| A. V. Aho and N. J. A. Sloane, Some doubly exponential sequences, Fib. Quart., 11 (1973), 429-437.
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FORMULA
| a(2n) = a(2n-1) + a(2n-2); a(2n+1) = a(2n-1)*a(2n); a(0) = 0; a(1) = 1
a(n)={a(n-1)+a(n-2), n even, a(n-1)*a(n-2), n odd}. a(0)=0. a(1)=1.
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PROG
| (PARI) a(n)=if(n<2, n>0, if(n%2, a(n-1)*a(n-2), a(n-1)+a(n-2)))
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CROSSREFS
| A001696(n)=A039941(2*n), A001697(n)=A039941(2*n+1).
Sequence in context: A123024 A079092 * A104700 A036761 A042979 A000018
Adjacent sequences: A039938 A039939 A039940 * A039942 A039943 A039944
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KEYWORD
| easy,nonn,nice
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AUTHOR
| Walter G. Carlini (541carlini(AT)charter.net)
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EXTENSIONS
| Additional comments from Michael Somos, May 19, 2000
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