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A001487 Expansion of (Product_{j>=1} (1-(-x)^j) - 1)^9 in powers of x.
(Formerly M4618 N1971)
4
1, -9, 36, -84, 117, -54, -177, 540, -837, 755, -54, -1197, 2535, -3204, 2520, -246, -3150, 6426, -8106, 7011, -2844, -3549, 10359, -15120, 15804, -11403, 2574, 8610, -18972, 25425, -25824, 18954, -6165, -10080, 25101, -35262, 37799, -31374, 17379, 1929 (list; graph; refs; listen; history; text; internal format)
OFFSET

9,2

REFERENCES

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

LINKS

Alois P. Heinz, Table of n, a(n) for n = 9..10000

H. Gupta, On the coefficients of the powers of Dedekind's modular form, J. London Math. Soc., 39 (1964), 433-440.

H. Gupta, On the coefficients of the powers of Dedekind's modular form (annotated and scanned copy)

MAPLE

g:= proc(n) option remember; `if`(n=0, 1, add(add([-d, d, -2*d, d]

      [1+irem(d, 4)], d=numtheory[divisors](j))*g(n-j), j=1..n)/n)

    end:

b:= proc(n, k) option remember; `if`(k=0, 1, `if`(k=1, `if`(n=0, 0, g(n)),

      (q-> add(b(j, q)*b(n-j, k-q), j=0..n))(iquo(k, 2))))

    end:

a:= n-> b(n, 9):

seq(a(n), n=9..48);  # Alois P. Heinz, Feb 07 2021

MATHEMATICA

nmax = 48; CoefficientList[Series[(Product[(1 - (-x)^j), {j, 1, nmax}] - 1)^9, {x, 0, nmax}], x] // Drop[#, 9] & (* Ilya Gutkovskiy, Feb 07 2021 *)

CROSSREFS

Sequence in context: A083353 A083014 A202287 * A175673 A285198 A230212

Adjacent sequences:  A001484 A001485 A001486 * A001488 A001489 A001490

KEYWORD

sign

AUTHOR

N. J. A. Sloane.

EXTENSIONS

Definition and offset edited by Ilya Gutkovskiy, Feb 07 2021

STATUS

approved

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Last modified May 10 22:15 EDT 2021. Contains 343780 sequences. (Running on oeis4.)