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Search: id:A112959
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| A112959 |
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a(1) = a(2) = a(3) = a(4) = a(5) = 1; for n>1: a(n+5) = (a(n))^2 + (a(n+1))^2 + (a(n+2))^2 + (a(n+3))^2 + (a(n+4))^2. |
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+0
3
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| 1, 1, 1, 1, 1, 5, 29, 869, 756029, 571580604869, 326704387862983487112029, 106735757048926752040856495274871386126283608845
(list; graph; listen)
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OFFSET
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1,6
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COMMENT
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A quadratic pentanacci sequence.
This is to A000283 as a pentanacci (A000322) is to Fibonacci. Primes in this begin a(6) = 5, and a(7) = 29. a(8), a(9), a(10) and a(11) are semiprime.
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EXAMPLE
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5^2 + 29^2 + 869^2 + 756029^2 + 571580604869^2 = 326704387862983487112029.
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CROSSREFS
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Cf. A000283, A000288.
Sequence in context: A103515 A069142 A072880 this_sequence A085553 A057208 A046842
Adjacent sequences: A112956 A112957 A112958 this_sequence A112960 A112961 A112962
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KEYWORD
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easy,nonn
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AUTHOR
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Jonathan Vos Post (jvospost2(AT)yahoo.com), Jan 02 2006
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