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A324535
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An analog of sigma(n)-n (A001065) for nonstandard factorization based on the sieve of Eratosthenes (A083221).
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3
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0, 1, 1, 3, 1, 6, 1, 7, 4, 8, 1, 16, 1, 10, 9, 15, 1, 21, 1, 22, 13, 14, 1, 36, 6, 16, 11, 28, 1, 42, 1, 31, 33, 20, 13, 55, 1, 22, 15, 50, 1, 66, 1, 40, 40, 26, 1, 76, 8, 43, 49, 46, 1, 54, 31, 64, 41, 32, 1, 108, 1, 34, 17, 63, 17, 144, 1, 58, 105, 74, 1, 123, 1, 40, 21, 64, 19, 78, 1, 106, 57, 44, 1, 172, 73, 46, 87, 92, 1, 201, 57, 76, 121
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OFFSET
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1,4
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LINKS
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FORMULA
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PROG
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(PARI)
up_to = 65537;
ordinal_transform(invec) = { my(om = Map(), outvec = vector(length(invec)), pt); for(i=1, length(invec), if(mapisdefined(om, invec[i]), pt = mapget(om, invec[i]), pt = 0); outvec[i] = (1+pt); mapput(om, invec[i], (1+pt))); outvec; };
A020639(n) = if(n>1, if(n>n=factor(n, 0)[1, 1], n, factor(n)[1, 1]), 1); \\ From A020639
v078898 = ordinal_transform(vector(up_to, n, A020639(n)));
A003961(n) = my(f = factor(n)); for (i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); \\ From A003961
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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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