Original entry on oeis.org
0, 1, 2, 6, 24, 240, 5040, 110880, 2298240, 47900160, 1117670400, 31654022400, 1064820556800, 39404587622400, 1532420002713600, 62512065487872000, 2723498636931072000, 128376129298120704000, 6524556605528113152000, 352829667414210674688000
Offset: 0
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nmax = 20; CoefficientList[InverseSeries[x - x^2 + x^3 - x^4 + O[x]^(nmax+1), x], x]*Range[0, nmax]! (* Jean-François Alcover, Jan 21 2019 *)
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seq(n)=Vec(serlaplace(serreverse(x - x^2 + x^3 - x^4 + O(x*x^n))), -(n+1)) \\ Andrew Howroyd, Nov 11 2018
Offset changed to zero and more terms added by
Robert Price, Oct 19 2017
A063022
Reversion of y - y^2 - y^3 - y^5.
Original entry on oeis.org
0, 1, 1, 3, 10, 39, 161, 698, 3126, 14360, 67276, 320229, 1544257, 7528577, 37044530, 183733552, 917598103, 4610484729, 23289784660, 118209987295, 602556082765, 3083273829240, 15832177371585, 81554320766310, 421320423560400, 2182395044437686, 11332298321692704
Offset: 0
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with(gfun):
F:= RootOf(y-y^2-y^3-y^5-x,y):
DE:=holexprtodiffeq(F,g(x)):
Rec:= diffeqtorec(DE,g(x),a(n)):
f:= rectoproc(Rec,a(n),remember):
map(f, [$0..50]); # Robert Israel, Jan 08 2019
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CoefficientList[InverseSeries[Series[y - y^2 - y^3 - y^5, {y, 0, 30}], x], x]
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def Reversion(gf, n=30):
R = PowerSeriesRing(QQ, 'x', n)
x = R.gen().O(n)
return list(R(gf).reverse())
Reversion(x - x^2 - x^3 - x^5, 24) # Peter Luschny, Jan 08 2019
A366024
Expansion of (1/x) * Series_Reversion( x*(1-x)*(1+x^5) ).
Original entry on oeis.org
1, 1, 2, 5, 14, 41, 125, 393, 1265, 4147, 13799, 46488, 158261, 543610, 1881730, 6557818, 22990323, 81026013, 286915275, 1020294605, 3642192301, 13047053600, 46885795710, 168979132425, 610640337099, 2212116899436, 8031940264223, 29224761233788
Offset: 0
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CoefficientList[InverseSeries[Series[x(1-x)(1+x^5),{x,0,28}],x]/x,x] (* Stefano Spezia, Sep 26 2023 *)
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a(n) = sum(k=0, n\5, (-1)^k*binomial(n+k, n)*binomial(2*n-5*k, n))/(n+1);
A063023
Reversion of y - y^2 - y^4 - y^5.
Original entry on oeis.org
0, 1, 1, 2, 6, 21, 77, 292, 1143, 4592, 18821, 78364, 330512, 1409149, 6063526, 26298592, 114849110, 504595293, 2228824203, 9891723114, 44087704836, 197255893945, 885630834120, 3988872011820, 18017892014655
Offset: 0
-
with(gfun):
F:= RootOf(y-y^2-y^4-y^5-x, y):
DE:=holexprtodiffeq(F, g(x)):
Rec:= diffeqtorec(DE, g(x), a(n)):
f:= rectoproc(Rec, a(n), remember):
map(f, [$0..50]);# Robert Israel, Jan 08 2019
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CoefficientList[InverseSeries[Series[y - y^2 - y^4 - y^5, {y, 0, 30}], x], x]
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a(n):=sum((sum(binomial(j,n-k-2*j-1)*binomial(k,j),j,floor((n-k-1)/3),floor((n-k-1)/2)))*binomial(n+k-1,n-1),k,0,n-1)/n; /* Vladimir Kruchinin, May 26 2011 */
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concat(0, Vec(serreverse(x - x^2 - x^4 - x^5 + O(x^30)))) \\ Michel Marcus, Jan 08 2019
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# uses[Reversion from A063022]
Reversion(x - x^2 - x^4 - x^5, 25) # Peter Luschny, Jan 08 2019
A063026
Reversion of y - y^2 + y^4 - y^5.
Original entry on oeis.org
0, 1, 1, 2, 4, 9, 21, 52, 135, 368, 1045, 3068, 9230, 28245, 87414, 272544, 854012, 2685897, 8473107, 26805994, 85045674, 270599945, 863529480, 2763745020, 8870777955, 28550721966, 92128996782, 298004209496, 966085311052
Offset: 0
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CoefficientList[InverseSeries[Series[y - y^2 + y^4 - y^5, {y, 0, 30}], x], x]
A364552
G.f. satisfies A(x) = 1 + x*A(x) + x^4*A(x)^3.
Original entry on oeis.org
1, 1, 1, 1, 2, 5, 11, 21, 39, 78, 169, 373, 808, 1727, 3719, 8153, 18100, 40315, 89770, 200250, 448755, 1010685, 2284295, 5173961, 11740697, 26699780, 60863291, 139045991, 318247190, 729572315, 1675085099, 3851795549, 8869990949, 20453679944, 47223844863
Offset: 0
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a(n) = sum(k=0, n\4, binomial(n-k, 3*k)*binomial(3*k, k)/(2*k+1));
A366023
Expansion of (1/x) * Series_Reversion( x*(1-x)*(1+x^4) ).
Original entry on oeis.org
1, 1, 2, 5, 13, 36, 104, 309, 940, 2915, 9184, 29328, 94747, 309180, 1017824, 3376693, 11279274, 37906330, 128085630, 434913555, 1483226921, 5078436800, 17450556480, 60159492600, 208013078910, 721205983737, 2506764055592, 8733076109732, 30489081691750
Offset: 0
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CoefficientList[InverseSeries[Series[x(1-x)(1+x^4),{x,0,29}],x]/x,x] (* Stefano Spezia, Sep 26 2023 *)
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a(n) = sum(k=0, n\4, (-1)^k*binomial(n+k, n)*binomial(2*n-4*k, n))/(n+1);
A217365
Series reversion of x + x^2 + x^3 + x^4 + x^5.
Original entry on oeis.org
1, -1, 1, -1, 1, 0, -6, 27, -83, 209, -455, 845, -1169, 272, 5916, -29070, 98040, -274075, 660859, -1351756, 2110020, -1186110, -8227260, 47128770, -170898624, 505121130, -1281947030, 2772309230, -4708067030, 3936320480, 13030540120, -90168747031, 348836671587, -1077316101393
Offset: 1
If y=x+x^2+x^3+x^4+x^5, then x=y -y^2 +y^3 -y^4 +y^5 -6*y^7 +27*y^8 -83*y^9 +...
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rec := 5*n*(5*n-1)*(5*n+1)*(5*n+2)*(5*n+3)*a(n)-(n+1)*(27906*n^4+198109*n^3+447051*n^2+405674*n+128400)*a(n+1)+(25*(n+2))*(1875*n^4+28312*n^3+141513*n^2+287228*n+204072)*a(n+2)+(250*(n+2))*(n+3)*(250*n^3+3031*n^2+11433*n+13668)*a(n+3)+(625*(n+2))*(n+3)*(n+4)*(75*n^2+662*n+1403)*a(n+4)+(3125*(n+2))*(n+3)*(n+4)*(n+5)*(6*n+29)*a(n+5)+(3125*(n+2))*(n+3)*(n+4)*(n+5)*(n+6)*a(n+6):
f:= gfun:-rectoproc({rec,a(1) = 1, a(2) = -1, a(3) = 1, a(4) = -1, a(5) = 1, a(6) = 0},a(n),remember):
map(f, [$1..50]); # Robert Israel, Jul 10 2015
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InverseSeries[x + x^2 + x^3 + x^4 + x^5 + O[x]^50][[3]] (* Vladimir Reshetnikov, Jul 09 2015 *)
RecurrenceTable[{5 (-8+3 n) (-21+5 n) (-19+5 n) (-18+5 n) (-17+5 n) (-17+6 n) (-11+6 n) a[-4+n]+4 (-3+n) (-11+6 n) (-4792620+7647427 n-4855116 n^2+1533029 n^3-240768 n^4+15048 n^5) a[-3+n]+30 (-3+n) (-2+n) (-1267420+2386123 n-1760222 n^2+636639 n^3-113004 n^4+7884 n^5) a[-2+n]+100 (-3+n) (-2+n) (-1+n) (-23+6 n) (-2310+2921 n-1152 n^2+144 n^3) a[-1+n]+125 (-3+n) (-2+n) (-1+n) n (-11+3 n) (-23+6 n) (-17+6 n) a[n]==0, a[1]==1, a[2]==-1, a[3]==1, a[4]==-1}, a, {n, 1, 40}] (* Vaclav Kotesovec, Aug 18 2015 *)
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Vec(serreverse(x + x^2 + x^3 + x^4 + x^5 + O(x^50))) \\ Michel Marcus, Aug 03 2015
A364539
G.f. satisfies A(x) = 1 + x*A(x) + x^3*A(x)^5.
Original entry on oeis.org
1, 1, 1, 2, 7, 22, 62, 182, 583, 1928, 6358, 21063, 70888, 241889, 831634, 2874584, 9995579, 34966279, 122938956, 434062141, 1538378816, 5471697241, 19525345791, 69880082323, 250767909528, 902123110483, 3252793321513, 11753570922933, 42553831219830
Offset: 0
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a(n) = sum(k=0, n\3, binomial(n+2*k, 5*k)*binomial(5*k, k)/(4*k+1));
A365756
G.f. satisfies A(x) = 1 + x*A(x) / (1 - x^3*A(x)^4).
Original entry on oeis.org
1, 1, 1, 1, 2, 7, 22, 58, 142, 363, 1014, 2966, 8645, 24824, 71189, 206742, 609159, 1809493, 5388804, 16073002, 48092377, 144532884, 436168716, 1320372837, 4006489208, 12183544414, 37132838866, 113426618425, 347191793705, 1064688271730, 3270387354434
Offset: 0
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a(n) = sum(k=0, n\3, binomial(n-2*k-1, k)*binomial(n+k+1, n-3*k)/(n+k+1));
Showing 1-10 of 11 results.
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