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A086538 n-th partial sum of A086537. 1
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 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

Every member has a unique prime signature. Conjecture: Every prime signature occurs in the sequence.

EXAMPLE

a(4) = 1+2+3+6 = 12, where 1, 2, 3 and 6 are the first four terms of A086537.

PROG

(PARI) print(1); ps(n) = local(f); f = factor(n); vecsort(f[, 2]); P = vector(70); psUsed(v, n) = for (i = 1, n - 1, if (v == P[i], return(1))); 0; 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; print(s); while(used[x], x++)); (Wasserman)

CROSSREFS

Cf. A086537.

Sequence in context: A032602 A116593 A109735 * A127563 A125627 A108757

Adjacent sequences:  A086535 A086536 A086537 * A086539 A086540 A086541

KEYWORD

nonn

AUTHOR

Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Aug 19 2003

EXTENSIONS

Corrected and extended by David Wasserman (wasserma(AT)spawar.navy.mil), Mar 15 2005

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Last modified February 17 02:31 EST 2012. Contains 205978 sequences.