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A173489 Partial sums of A000140. 0
1, 2, 4, 10, 32, 133, 706, 4542, 33770, 284519, 2694100, 28292286, 324935676, 4052477864, 793359552994, 793359552994, 12294933375782, 202713354823112, 3547535843321377, 65667058958304601, 1280634899889213903 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

After 2, the next prime is a(41) = 305549535052620874099715701517119130422273792081.

LINKS

Table of n, a(n) for n=1..21.

FORMULA

a(n) = Sum_{i=1..n} A000140(i).

a(n) ~ 6 * n^(n-1) / exp(n). - Vaclav Kotesovec, Oct 27 2016

EXAMPLE

a(21) = 1 + 1 + 2 + 6 + 22 + 101 + 573 + 3836 + 29228 + 250749 + 2409581 + 25598186 + 296643390 + 3727542188 + 50626553988 + 738680521142 + 11501573822788 + 190418421447330 + 3344822488498265 + 62119523114983224 + 1214967840930909302.

MATHEMATICA

f[n_] := Max@ CoefficientList[ Expand@ Product[ Sum[x^i, {i, 0, j}], {j, n - 1}], x]; Accumulate@ Array[f, 21]

CROSSREFS

Cf. A000140, A008302.

Sequence in context: A054091 A056593 A154219 * A089476 A220028 A006397

Adjacent sequences:  A173486 A173487 A173488 * A173490 A173491 A173492

KEYWORD

easy,nonn

AUTHOR

Jonathan Vos Post, Feb 19 2010

STATUS

approved

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Last modified December 9 00:45 EST 2016. Contains 278959 sequences.