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Revision History for A280917 (Underlined text is an addition; strikethrough text is a deletion.)

Showing entries 1-10 | older changes
A280917 Expansion of 1/(1 - x - Sum_{k>=1} x^prime(k)).
(history; published version)
#11 by N. J. A. Sloane at Thu Mar 09 14:48:35 EST 2017
STATUS

proposed

approved

#10 by Joerg Arndt at Thu Mar 09 12:32:40 EST 2017
STATUS

editing

proposed

#9 by Joerg Arndt at Thu Mar 09 12:32:25 EST 2017
PROG

(PARI) print(Vec(1 / (1 - x - sum(k=1, 100, x^prime(k))) + O(x^100))); )) \\ _Indranil Ghosh_, Mar 09 2017

\\ Indranil Ghosh, Mar 09 2017

STATUS

proposed

editing

Discussion
Thu Mar 09 12:32
Joerg Arndt: Useless use of "print".  Fixed.
#8 by Indranil Ghosh at Thu Mar 09 12:24:14 EST 2017
STATUS

editing

proposed

#7 by Indranil Ghosh at Thu Mar 09 12:23:31 EST 2017
PROG

(PARI) aprint(Vec(1 / (1 - x) = - sum(k=1, 100, x^prime(k)); ))) + O(x^100)));

print(Vec(1 / (1 - x - a(x)) + O(x^100))); \\ Indranil Ghosh, Mar 09 2017

\\ Indranil Ghosh, Mar 09 2017

STATUS

proposed

editing

#6 by Indranil Ghosh at Thu Mar 09 12:21:12 EST 2017
STATUS

editing

proposed

#5 by Indranil Ghosh at Thu Mar 09 12:19:48 EST 2017
LINKS

Indranil Ghosh, <a href="/A280917/b280917.txt">Table of n, a(n) for n = 0..99</a>

PROG

(PARI) a(x) = sum(k=1, 100, x^prime(k));

print(Vec(1 / (1 - x - a(x)) + O(x^100))); \\ Indranil Ghosh, Mar 09 2017

STATUS

approved

editing

#4 by N. J. A. Sloane at Wed Jan 11 03:23:49 EST 2017
STATUS

proposed

approved

#3 by Ilya Gutkovskiy at Tue Jan 10 16:30:55 EST 2017
STATUS

editing

proposed

#2 by Ilya Gutkovskiy at Tue Jan 10 16:21:55 EST 2017
NAME

allocated for Ilya Gutkovskiy

Expansion of 1/(1 - x - Sum_{k>=1} x^prime(k)).

DATA

1, 1, 2, 4, 7, 14, 26, 50, 95, 180, 343, 652, 1240, 2359, 4486, 8532, 16227, 30862, 58697, 111636, 212321, 403814, 768015, 1460691, 2778094, 5283667, 10049027, 19112282, 36349721, 69133673, 131485594, 250072951, 475614693, 904573387, 1720411555, 3272057256, 6223138101, 11835809946, 22510571803, 42812941849

OFFSET

0,3

COMMENTS

Number of compositions (ordered partitions) of n into prime parts (1 included) (A008578).

LINKS

<a href="/index/Com#comp">Index entries for sequences related to compositions</a>

FORMULA

G.f.: 1/(1 - x - Sum_{k>=1} x^prime(k)).

EXAMPLE

a(4) = 7 because we have [3, 1], [2, 2], [2, 1, 1], [1, 3], [1, 2, 1], [1, 1, 2] and [1, 1, 1, 1].

MATHEMATICA

nmax = 39; CoefficientList[Series[1/(1 - x - Sum[x^Prime[k], {k, 1, nmax}]), {x, 0, nmax}], x]

CROSSREFS

Cf. A000607, A002124, A008578, A023360, A034891, A036497.

KEYWORD

allocated

nonn

AUTHOR

Ilya Gutkovskiy, Jan 10 2017

STATUS

approved

editing

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Last modified August 30 00:57 EDT 2024. Contains 375520 sequences. (Running on oeis4.)