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A086538
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n-th partial sum of A086537.
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1
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1, 3, 6, 12, 16, 24, 36, 49, 60, 70, 96, 112, 144, 168, 210, 240, 288, 343, 360, 396, 448, 512, 630, 648, 675, 720, 729, 768, 840, 896, 1000, 1080, 1120, 1260, 1344, 1440, 1600, 1728, 1920, 2160, 2304, 2520, 2640, 2700, 2880, 3125, 3200, 3456, 3570, 3584, 3888
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OFFSET
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1,2
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COMMENTS
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Every member has a unique prime signature. Conjecture: Every prime signature occurs in the sequence.
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LINKS
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EXAMPLE
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a(4) = 1+2+3+6 = 12, where 1, 2, 3 and 6 are the first four terms of A086537.
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PROG
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(PARI) ps(n) = local(f); f = factor(n); vecsort(f[, 2]);
psUsed(v, n) = for (i = 1, n - 1, if (v == P[i], return(1))); 0;
print1(1, ", "); P = vector(70); used = vector(10000); x = 2; s = 1; for (n = 1, 70, i = x; v = ps(s + i); while (psUsed(v, n), i++; while (used[i], i++); v = ps(s + i)); used[i] = 1; P[n] = v; s += i; print1(s, ", "); while(used[x], x++)); \\ David Wasserman, Mar 15 2005
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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