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 1-2 of 2 results.

A266521 E.g.f.: Log( Sum_{n>=0} (n + y)^(2*n) * x^n/n! ) = Sum_{n>=1} Sum_{k=0..n+1} T(n,k) * x^n*y^k/n!, as a triangle of coefficients T(n,k) read by rows.

Original entry on oeis.org

1, 2, 1, 15, 28, 18, 4, 683, 1278, 933, 316, 42, 62038, 117440, 92680, 38240, 8272, 752, 9342629, 17880090, 14855385, 6881640, 1880340, 288048, 19360, 2100483216, 4054752672, 3490688496, 1743156480, 547098240, 108228192, 12523584, 654912, 658746323647, 1279910119670, 1130161189549, 594323331364, 204256939502, 47125635760, 7147508032, 652959872, 27546736, 274730459045232, 536368375356928, 482514140459520, 263340552849920, 96404466197760, 24628940050176, 4404380994048, 533057051648, 39701769216, 1388207872
Offset: 1

Views

Author

Paul D. Hanna, Jan 01 2016

Keywords

Comments

Row sums form A266520, coefficients in Log( Sum_{n>=0} (n+1)^(2*n) * x^n/n! ).
Column 0 forms A266519, coefficients in log( Sum_{n>=0} n^(2*n) * x^n/n! ).
Rightmost border is A266526.

Examples

			E.g.f.: A(x,y) = x * (1 + 2*y + y^2) +
x^2/2! * (15 + 28*y + 18*y^2 + 4*y^3) +
x^3/3! * (683 + 1278*y + 933*y^2 + 316*y^3 + 42*y^4) +
x^4/4! * (62038 + 117440*y + 92680*y^2 + 38240*y^3 + 8272*y^4 + 752*y^5) +
x^5/5! * (9342629 + 17880090*y + 14855385*y^2 + 6881640*y^3 + 1880340*y^4 + 288048*y^5 + 19360*y^6) +
x^6/6! * (2100483216 + 4054752672*y + 3490688496*y^2 + 1743156480*y^3 + 547098240*y^4 + 108228192*y^5 + 12523584*y^6 + 654912*y^7) +...
where
exp(A(x,y)) = 1 + (1 + y)*x + (2 + y)^4*x^2/2! + (3 + y)^6*x^3/3! + (4 + y)^8*x^4/4! + (5 + y)^10*x^5/5! + (6 + y)^12*x^6/6! +...
This triangle begins:
1, 2, 1;
15, 28, 18, 4;
683, 1278, 933, 316, 42;
62038, 117440, 92680, 38240, 8272, 752;
9342629, 17880090, 14855385, 6881640, 1880340, 288048, 19360;
2100483216, 4054752672, 3490688496, 1743156480, 547098240, 108228192, 12523584, 654912;
658746323647, 1279910119670, 1130161189549, 594323331364, 204256939502, 47125635760, 7147508032, 652959872, 27546736;
274730459045232, 536368375356928, 482514140459520, 263340552849920, 96404466197760, 24628940050176, 4404380994048, 533057051648, 39701769216, 1388207872;
147034646085347145, 288100398039817266, 262835789583073329, 147457696629622032, 56514667400140392, 15510808994500512, 3097157140510272, 445604738641920, 44324678623680, 2758053332736, 81621893376; ...
		

Crossrefs

Programs

  • PARI
    {T(n,k) = n! * polcoeff( polcoeff( log( sum(m=0,n+1, (m + y)^(2*m) *x^m/m! ) +x*O(x^n) ),n,x), k,y)}
    for(n=1,10, for(k=0,n+1, print1(T(n,k),", "));print(""))

A266519 E.g.f.: Log( Sum_{n>=0} n^(2*n) * x^n/n! ).

Original entry on oeis.org

1, 15, 683, 62038, 9342629, 2100483216, 658746323647, 274730459045232, 147034646085347145, 98233150285382861440, 80135799180812308488851, 78391682820973752124219392, 90580896598669336052642926957, 122061249780317702369474934804480, 189729092979696204185243101261174695, 336959230406443195042628708778757175296, 678101445794980815528276151098815880395921
Offset: 1

Views

Author

Paul D. Hanna, Dec 31 2015

Keywords

Crossrefs

Cf. A266520.

Programs

  • PARI
    {a(n) = n! * polcoeff( log( sum(m=0,n, m^(2*m) * x^m/m!) +x*O(x^n)), n)}
    for(n=1,20,print1(a(n),", "))
Showing 1-2 of 2 results.