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A318887
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Filter sequence related to the differences of prime factors of n.
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3
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1, 2, 2, 3, 2, 4, 2, 5, 3, 6, 2, 7, 2, 8, 9, 10, 2, 11, 2, 12, 13, 14, 2, 15, 3, 16, 5, 17, 2, 18, 2, 19, 20, 21, 9, 22, 2, 23, 24, 25, 2, 26, 2, 27, 28, 29, 2, 30, 3, 31, 32, 33, 2, 34, 35, 36, 37, 38, 2, 39, 2, 40, 41, 42, 20, 43, 2, 44, 45, 46, 2, 47, 2, 48, 49, 50, 13, 51, 2, 52, 10, 53, 2, 54, 55, 56, 57, 58, 2, 59, 35, 60, 61, 62, 32, 63, 2, 64, 65, 66, 2
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OFFSET
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1,2
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COMMENTS
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Restricted growth sequence transform of A318885.
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LINKS
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PROG
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(PARI)
up_to = 100000;
rgs_transform(invec) = { my(om = Map(), outvec = vector(length(invec)), u=1); for(i=1, length(invec), if(mapisdefined(om, invec[i]), my(pp = mapget(om, invec[i])); outvec[i] = outvec[pp] , mapput(om, invec[i], i); outvec[i] = u; u++ )); outvec; };
A318885(n) = if(1==n, n, my(f=factor(n), m=2^f[1, 2], i=1); for(k=2, #f~, i += (f[k, 1]-f[k-1, 1]); m *= prime(i)^f[k, 2]); (m));
v318887 = rgs_transform(vector(up_to, n, A318885(n)));
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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