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A120761
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a(1) =a(2) =1. a(n) = a(n-1) + (largest noncomposite {1 or prime} among the first n-2 terms of the sequence).
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2
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1, 1, 2, 3, 5, 8, 13, 18, 31, 44, 75, 106, 137, 168, 305, 442, 579, 716, 853, 990, 1843, 2696, 3549, 4402, 5255, 6108, 6961, 7814, 14775, 21736, 28697, 35658, 64355, 93052, 121749, 150446, 179143, 207840, 386983, 566126, 745269, 924412, 1103555
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,3
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EXAMPLE
| Among the first 10 terms of the sequence, 31 is the largest noncomposite. So a(12) = a(11) + 31 = 75 + 31 = 106.
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MAPLE
| isA008578 := proc(n) if n = 1 or isprime(n) then true ; else false ; fi ; end: A120761 := proc(nmin) local a, lnpr, k; a := [1, 1, 2] ; while nops(a) < nmin do lnpr :=0 ; for k in [op(1..nops(a)-1, a)] do if isA008578(k) then lnpr := max(lnpr, k) ; fi ; od: a := [op(a), a[ -1]+lnpr] ; od: RETURN(a) ; end: A120761(80) ; - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Sep 18 2007
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CROSSREFS
| Cf. A120760.
Sequence in context: A001149 A144117 A081612 * A178741 A045842 A200462
Adjacent sequences: A120758 A120759 A120760 * A120762 A120763 A120764
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KEYWORD
| nonn
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AUTHOR
| Leroy Quet Jul 03 2006
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EXTENSIONS
| More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Sep 18 2007
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