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.

A128570 Rectangular table, read by antidiagonals, where the g.f. of row n, R(x,n), satisfies: R(x,n) = 1 + (n+1)*x*R(x,n+1)^2 for n>=0.

Original entry on oeis.org

1, 1, 1, 1, 2, 4, 1, 3, 12, 28, 1, 4, 24, 114, 276, 1, 5, 40, 288, 1440, 3480, 1, 6, 60, 580, 4440, 22368, 53232, 1, 7, 84, 1020, 10560, 82080, 409248, 955524, 1, 8, 112, 1638, 21420, 226560, 1752000, 8585088, 19672320, 1, 9, 144, 2464, 38976, 523320, 5532960, 42178800, 202733760, 456803328, 1, 10, 180, 3528, 65520, 1068480, 14399280, 150570240, 1127335680, 5317663680, 11810032896, 1, 11, 220, 4860, 103680, 1991808, 32716992, 437433780, 4501422240, 33073099200, 153345634560, 336463895808
Offset: 0

Views

Author

Paul D. Hanna, Mar 11 2007

Keywords

Comments

Row r > 0 is asymptotic to 2^(2*r) * n^r * A128318(n) / (3^r * r!). - Vaclav Kotesovec, Mar 19 2016

Examples

			Row g.f.s satisfy: R(x,0) = 1 + x*R(x,1)^2, R(x,1) = 1 + 2x*R(x,2)^2,
R(x,2) = 1 + 3x*R(x,3)^2, R(x,3) = 1 + 4x*R(x,4)^2, ...
where the initial rows begin:
R(x,0):[1,1,4,28,276,3480,53232,955524,19672320,456803328,...];
R(x,1):[1,2,12,114,1440,22368,409248,8585088,202733760,...];
R(x,2):[1,3,24,288,4440,82080,1752000,42178800,1127335680,...];
R(x,3):[1,4,40,580,10560,226560,5532960,150570240,4501422240,...];
R(x,4):[1,5,60,1020,21420,523320,14399280,437433780,14479664640,...];
R(x,5):[1,6,84,1638,38976,1068480,32716992,1098069504,39896236800,...];
R(x,6):[1,7,112,2464,65520,1991808,67189248,2469837888,97765355520,..];
R(x,7):[1,8,144,3528,103680,3461760,127569600,5098406400,...];
R(x,8):[1,9,180,4860,156420,5690520,227470320,9821970180,...];
R(x,9):[1,10,220,6490,227040,8939040,385265760,17875608960,..].
		

Crossrefs

Rows: A128318, A128571, A128572, A128573, A128574, A128575, A128576; A128577 (square of row 0), A128578 (main diagonal), A128579 (antidiagonal sums).

Programs

  • PARI
    {T(n,k)=local(A=1+(n+k+1)*x); for(j=0,k,A=1+(n+k+1-j)*x*A^2 +x*O(x^k));polcoeff(A,k)}
    for(n=0, 12, for(k=0, 10, print1(T(n, k), ", ")); print(""))