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Search: id:A119617
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| A119617 |
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Integers of the form c(n)/b(n) where c(n+1)=c(n)+(n+1)^4 with c(0)=1 and b(n+1)=b(n)+(n+1)^2 with b(0)=1. |
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11
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| 1, 7, 25, 43, 79, 109, 163, 205, 277, 331, 421, 487, 595, 673, 799, 889, 1033, 1135, 1297, 1411, 1591, 1717, 1915, 2053, 2269, 2419, 2653, 2815, 3067, 3241, 3511, 3697, 3985, 4183, 4489, 4699, 5023, 5245, 5587, 5821, 6181, 6427, 6805, 7063, 7459, 7729
(list; graph; listen)
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OFFSET
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1,2
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FORMULA
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The sequence is the union of the numbers 15*n^2-21*n+7 and 15*n^2-9*n+1 with n>=0
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EXAMPLE
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c(0)/b(0)=1/1=1
c(3)/b(3)=(1+2^4+3^4)/(1+2^2+3^2)= (1+16+81)/(1+4+9)= 98/14 = 7
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MAPLE
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P:=proc(n) local f, i, j, nu, de; nu:=0; de:=0; for i from 1 by 1 to n do nu:=nu+i^4; de:=de+i^2; f:=nu/de; if trunc(f)=f then print(f); fi; od; end: P(1000);
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CROSSREFS
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Sequence in context: A140716 A141393 A075927 this_sequence A102027 A031294 A137380
Adjacent sequences: A119614 A119615 A119616 this_sequence A119618 A119619 A119620
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KEYWORD
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easy,nonn
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AUTHOR
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Paolo P. Lava & Giorgio Balzarotti (ppl(AT)spl.at), Jun 06 2006
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