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Search: id:A134192
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| A134192 |
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a(0) = a(1) = 1. a(n) = sum{p|n} a(n-p), where the sum is over all distinct primes p that divide n. |
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1
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| 1, 1, 1, 1, 1, 1, 2, 1, 2, 2, 3, 1, 5, 1, 6, 8, 6, 1, 14, 1, 22, 20, 23, 1, 43, 22, 44, 43, 64, 1, 129, 1, 129, 152, 130, 193, 282, 1, 283, 326, 476, 1, 995, 1, 1147, 1471, 1148, 1, 2619, 995, 4090, 2749, 4416, 1, 7165, 5237, 8160, 7448, 8161, 1, 20846, 1, 20847, 29006
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OFFSET
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0,7
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EXAMPLE
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The distinct primes that divide 12 are 2 and 3. So a(12) = a(12-2) + a(12-3) = a(10) + a(9) = 3 + 2 = 5.
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MATHEMATICA
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a = {1, 1}; For[n = 2, n < 80, n++, s = 0; For[i = 1, i < Length[Divisors[n]] + 1, i++, If[PrimeQ[Divisors[n][[i]]], s = s + a[[n - Divisors[n][[i]] + 1]]]]; AppendTo[a, s]]; a [From Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Aug 30 2008]
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CROSSREFS
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Sequence in context: A133755 A070104 A131085 this_sequence A060426 A126305 A088431
Adjacent sequences: A134189 A134190 A134191 this_sequence A134193 A134194 A134195
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KEYWORD
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nonn
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AUTHOR
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Leroy Quet (q1qq2qqq3qqqq(AT)yahoo.com), Jan 13 2008
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EXTENSIONS
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More terms from Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Aug 30 2008
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