cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-3 of 3 results.

A296173 G.f. equals the logarithm of the e.g.f. of A296172.

Original entry on oeis.org

1, -3, -30, -2686, -517311, -173118807, -88535206152, -63977172334344, -61971659588102940, -77470793599569049440, -121439997599825393413344, -233353875172602479932391040, -539638027429765922735002220880, -1479049138515818646669055218090480, -4742815067612592169849894663392228480, -17597031102801426396121130730318359114880, -74817150772352720408567833273371047298417408
Offset: 1

Views

Author

Paul D. Hanna, Dec 07 2017

Keywords

Comments

E.g.f. G(x) of A296172 satisfies: [x^(n-1)] G(x)^(n^3) = [x^n] G(x)^(n^3) for n>=1.

Examples

			G.f. A(x) = x - 3*x^2 - 30*x^3 - 2686*x^4 - 517311*x^5 - 173118807*x^6 - 88535206152*x^7 - 63977172334344*x^8 - 61971659588102940*x^9 - 77470793599569049440*x^10 - 121439997599825393413344*x^11 - 233353875172602479932391040*x^12 - 539638027429765922735002220880*x^13 - 1479049138515818646669055218090480*x^14 - 4742815067612592169849894663392228480*x^15 +...
such that
G(x) = exp(A(x)) = 1 + x - 5*x^2/2! - 197*x^3/3! - 65111*x^4/4! - 62390159*x^5/5! - 125012786669*x^6/6! - 447082993406405*x^7/7! - 2583111044504384687*x^8/8! - 22511408975342644804991*x^9/9! - 281350305428215911326408789*x^10/10! - 4850582201056517165575319399909*x^11/11! - 111834955668396093904661955538037255*x^12/12! +...
satisfies [x^(n-1)] G(x)^(n^3) = [x^n] G(x)^(n^3) for n>=1.
Series_Reversion(A(x)) = x + 3*x^2 + 48*x^3 + 3271*x^4 + 575163*x^5 + 185377116*x^6 + 93039467356*x^7 + 66505075585875*x^8 + 63970743282062646*x^9 + 79580632411431634441*x^10 + 124299284968805234137968*x^11 + 238188439678208173206500760*x^12 +...+ A295813(n)*x^n +...
		

Crossrefs

Programs

  • PARI
    {a(n) = my(A=[1]); for(i=1,n+1, A=concat(A,0); V=Vec(Ser(A)^((#A-1)^3)); A[#A] = (V[#A-1] - V[#A])/(#A-1)^3 ); polcoeff(log(Ser(A)),n)}
    for(n=1,30,print1(a(n),", "))

Formula

a(n) ~ -sqrt(1-c) * 3^(3*n - 3) * n^(2*n - 7/2) / (sqrt(2*Pi) * c^n * (3-c)^(2*n - 3) * exp(2*n)), where c = -LambertW(-3*exp(-3)) = -A226750. - Vaclav Kotesovec, Oct 13 2020

A295812 G.f. A(x) satisfies: G(A(x)) = exp(x), where G(x) equals the e.g.f. of A296170.

Original entry on oeis.org

1, 1, 3, 19, 226, 4259, 110514, 3626207, 143043592, 6567931068, 343278693103, 20092744961109, 1300754163383700, 92223505422990050, 7104166647498916816, 590661172651143976231, 52710327177111760030280, 5024720072707894279118236, 509553454073135435969780828, 54771493019290133717304608756, 6220332385328132888848047735930, 744260531662484056612631555859467
Offset: 1

Views

Author

Paul D. Hanna, Dec 09 2017

Keywords

Comments

E.g.f. G(x) of A296170 satisfies: [x^(n-1)] G(x)^(n^2) = [x^n] G(x)^(n^2) for n>=1.

Examples

			G.f. A(x) = x + x^2 + 3*x^3 + 19*x^4 + 226*x^5 + 4259*x^6 + 110514*x^7 + 3626207*x^8 + 143043592*x^9 + 6567931068*x^10 + 343278693103*x^11 + 20092744961109*x^12 + 1300754163383700*x^13 + 92223505422990050*x^14 + 7104166647498916816*x^15 +...
The series reversion equals the logarithm of the e.g.f. of A296170, which begins:
Series_Reversion(A(x)) = x - x^2 - x^3 - 9*x^4 - 134*x^5 - 2852*x^6 - 79096*x^7 - 2699480*x^8 - 109201844*x^9 - 5100872244*x^10 - 269903909820*x^11 - 15944040740604*x^12 - 1039553309158964*x^13 - 74123498185170292*x^14 - 5736368141560365292*x^15 +...+ A296171(n)*x^n +...
		

Crossrefs

Programs

  • PARI
    {a(n) = my(A=[1]); for(i=1,n+1, A=concat(A,0); V=Vec(Ser(A)^((#A-1)^2)); A[#A] = (V[#A-1] - V[#A])/(#A-1)^2 ); polcoeff(serreverse(log(Ser(A))),n)}
    for(n=1,30,print1(a(n),", "))

Formula

G.f. is the series reversion of the logarithm of the e.g.f. of A296170.
a(n) ~ c * d^n * n! / n^3, where d = -4/(LambertW(-2*exp(-2)) * (2 + LambertW(-2*exp(-2)))) = 6.17655460948348035823168... and c = (2 + LambertW(-2*exp(-2)))^2 * sqrt(-LambertW(-2*exp(-2))*(1 + LambertW(-2*exp(-2)))) / (8*sqrt(2)*Pi) = 0.0350943105... - Vaclav Kotesovec, Dec 22 2017, updated Aug 06 2018

A295814 G.f. A(x) satisfies: G(A(x)) = exp(x), where G(x) equals the e.g.f. of A296174.

Original entry on oeis.org

1, 7, 591, 360071, 696409901, 2958728428011, 23164541753169117, 300801581861406441263, 6028093825088113213286946, 176753891171734450100762135773, 7275100380834838623971362431809230, 406542590169784279153263825042856310627, 30008177367626616771665421796780382440931316, 2859139755874441545650368872575815286528870509597
Offset: 1

Views

Author

Paul D. Hanna, Dec 09 2017

Keywords

Comments

E.g.f. G(x) of A296174 satisfies: [x^(n-1)] G(x)^(n^4) = [x^n] G(x)^(n^4) for n>=1.

Examples

			G.f. A(x) = x + 7*x^2 + 591*x^3 + 360071*x^4 + 696409901*x^5 + 2958728428011*x^6 + 23164541753169117*x^7 + 300801581861406441263*x^8 +...
Series_Reversion(A(x)) = x - 7*x^2 - 493*x^3 - 341101*x^4 - 680813601*x^5 - 2923660883625*x^6 - 22996362478599551*x^7 - 299331006952284448127*x^8 - 6006951481145880962408552*x^9 +...+ A296175(n)*x^n +...
G(x) = exp(Series_Reversion(A(x))) = 1 + x - 13*x^2/2! - 2999*x^3/3! - 8197751*x^4/4! - 81738176899*x^5/5! - 2105524335759389*x^6/6! - 115916378979693710123*x^7/7! - 12069952631345502122877199*x^8/8! - 2179911119857340269414590758951*x^9/9! +...+ A296174(n)*x^n/n! +...
which satisfies [x^(n-1)] G(x)^(n^4) = [x^n] G(x)^(n^4) for n>=1.
		

Crossrefs

Programs

  • PARI
    {a(n) = my(A=[1]); for(i=1,n+1, A=concat(A,0); V=Vec(Ser(A)^((#A-1)^4)); A[#A] = (V[#A-1] - V[#A])/(#A-1)^4 ); polcoeff(serreverse(log(Ser(A))),n)}
    for(n=1,30,print1(a(n),", "))

Formula

G.f. is the series reversion of the logarithm of the e.g.f. of A296174.
a(n) ~ sqrt(1-c) * 2^(8*n - 17/2) * n^(3*n - 9/2) / (sqrt(Pi) * c^n * (4-c)^(3*n - 4) * exp(3*n)), where c = -LambertW(-4*exp(-4)) = 0.07930960512711365643910864... - Vaclav Kotesovec, Dec 22 2017, updated Oct 13 2020
Showing 1-3 of 3 results.