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Search: id:A071988
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| A071988 |
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Triple Peano sequence: a list of triples (x,y,z) starting at (1,1,1); then x'=x+1, y'=y+x, z'=z+y. |
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3
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| 2, 2, 2, 3, 4, 4, 5, 11, 15, 7, 22, 42, 11, 56, 176, 13, 79, 299, 17, 137, 697, 19, 172, 988, 23, 254, 1794, 29, 407, 3683, 31, 466, 4526, 37, 667, 7807, 41, 821, 10701, 43, 904, 12384, 47, 1082, 16262, 53, 1379, 23479, 59, 1712, 32568, 61, 1831, 36051, 67, 2212
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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a(3k+1) are the primes (A000040), a(3k+2) are A072205 and a(3k) are A072206.
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EXAMPLE
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x'=x+1=1+1=2, y'=y+x=1+1=2, z'=z+y=1+1=2.
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MATHEMATICA
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seq[n_Integer?Positive] := Module[{fn01 = 1, fn10 = 1, fnout = 1}, Do[{fn10, fn01, fnout} = {fn10 + 1, fn01 + fn10, fn01 + fnout}, {n - 1}]; {fn10, fn01, fnout}]; Flatten[ Table[ seq[ Prime[n]], {n, 1, 100}]]
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PROGRAM
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(PARI) a(n)=subst([x, x*(x-1)/2+1, (x^3-3*x^2+8*x)/6], x, prime(1+(n-1)\3))[1+(n-1)%3]
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CROSSREFS
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Cf. A072205 & A072206.
Sequence in context: A088044 A029051 A079398 this_sequence A029050 A066920 A035381
Adjacent sequences: A071985 A071986 A071987 this_sequence A071989 A071990 A071991
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KEYWORD
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nonn
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AUTHOR
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Roger L. Bagula (rlbagulatftn(AT)yahoo.com), Jun 17 2002
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EXTENSIONS
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Edited by Robert G. Wilson v (rgwv(AT)rgwv.com), Jul 03 2002
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