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 1-5 of 5 results.

A274571 Column 0 of triangle A274570.

Original entry on oeis.org

1, 1, 7, 127, 4377, 245481, 20391523, 2354116899, 360734454993, 70865037282673, 17367953099244051, 5195706189463681299, 1863485648739527246569, 789370246456579516316121, 389929989984983783920348611, 222178771969671609391720410691, 144648509476124539709343154760897, 106712830948451223242311469280356609, 88557950557114913966623605248882438755, 82132537612235618834557329353828430430755
Offset: 0

Views

Author

Paul D. Hanna, Jun 28 2016

Keywords

Comments

Triangle A274570 transforms diagonals in the array A274390 of coefficients of successive iterations of Euler's tree function (A000169).

Crossrefs

Programs

  • PARI
    {T(n, k)=local(F=x,
    LW=serreverse(x*exp(-x+x*O(x^(n+2)))), M, N, P, m=max(n, k));
    M=matrix(m+3, m+3, r, c, F=x; for(i=1, r+c-2, F=subst(F, x, LW)); polcoeff(F, c));
    N=matrix(m+1, m+1, r, c, M[r, c]);
    P=matrix(m+1, m+1, r, c, M[r+1, c]);
    (n-k)!*(P~*N~^-1)[n+1, k+1]}
    /* Print triangle A274570: */
    for(n=0,10,for(k=0,n,print1(T(n,k),", "));print(""))
    /* Print this sequence, which is column 0 */
    for(n=0,20,print1(T(n,0),", "))

A274572 Column 1 of triangle A274570.

Original entry on oeis.org

1, 2, 20, 470, 19912, 1326382, 127677580, 16767030632, 2880746218304, 627213971899610, 168767535712912684, 54994347890521005100, 21342142821229037730064, 9726400286221416303901358, 5143644030714149522751534524, 3124088412968372614077895431788, 2159818183532141245447039295746240, 1686295004858842334963772859214802354, 1476540037893212558044217633785452773068, 1440964034588041764141738802548853847618732
Offset: 0

Views

Author

Paul D. Hanna, Jun 28 2016

Keywords

Comments

Triangle A274570 transforms diagonals in the array A274390 of coefficients of successive iterations of Euler's tree function (A000169).

Crossrefs

Programs

  • PARI
    {T(n, k)=local(F=x,
    LW=serreverse(x*exp(-x+x*O(x^(n+2)))), M, N, P, m=max(n, k));
    M=matrix(m+3, m+3, r, c, F=x; for(i=1, r+c-2, F=subst(F, x, LW)); polcoeff(F, c));
    N=matrix(m+1, m+1, r, c, M[r, c]);
    P=matrix(m+1, m+1, r, c, M[r+1, c]);
    (n-k)!*(P~*N~^-1)[n+1, k+1]}
    /* Print triangle A274570: */
    for(n=0,10,for(k=0,n,print1(T(n,k),", "));print(""))
    /* Print this sequence, which is column 1 */
    for(n=0,20,print1(T(n+1,1),", "))

A274573 Column 2 of triangle A274570.

Original entry on oeis.org

1, 3, 39, 1125, 56505, 4354923, 476265591, 70056231213, 13329387478113, 3184105899176739, 932720103991595919, 328710383679927689157, 137188135970104212440721, 66909975066823379752742835, 37706189062081696231083478647, 24312515006613477431766856702797, 17784145956730483348850500758855969, 14647274671009402833580157237962722147, 13492886769176913829412675003231182928079
Offset: 0

Views

Author

Paul D. Hanna, Jun 28 2016

Keywords

Comments

Triangle A274570 transforms diagonals in the array A274390 of coefficients of successive iterations of Euler's tree function (A000169).

Crossrefs

Programs

  • PARI
    {T(n, k)=local(F=x,
    LW=serreverse(x*exp(-x+x*O(x^(n+2)))), M, N, P, m=max(n, k));
    M=matrix(m+3, m+3, r, c, F=x; for(i=1, r+c-2, F=subst(F, x, LW)); polcoeff(F, c));
    N=matrix(m+1, m+1, r, c, M[r, c]);
    P=matrix(m+1, m+1, r, c, M[r+1, c]);
    (n-k)!*(P~*N~^-1)[n+1, k+1]}
    /* Print triangle A274570: */
    for(n=0,10,for(k=0,n,print1(T(n,k),", "));print(""))
    /* Print this sequence, which is column 2 */
    for(n=0,20,print1(T(n+2,2),", "))

A274574 Central terms of triangle A274570.

Original entry on oeis.org

1, 2, 39, 2188, 247465, 47290506, 13732594855, 5645761143968, 3124313624563281, 2240929551882269890, 2023001689428835457551, 2245340983227461222262600, 3005921392102922941037743561, 4777188534537036418050441999458, 8892651921874938986718539648539335, 19167346139929272962512547586833106016, 47363669252787891219004826832547428944065, 133017373943189884985366059167726505579520322, 421334607602498277189468756234637306051458074191, 1495034827615578030423476599123008111000477082402040, 5906697677063490360959940664316005473632429506949424681
Offset: 0

Views

Author

Paul D. Hanna, Jun 28 2016

Keywords

Comments

Triangle A274570 transforms diagonals in the array A274390 of coefficients of successive iterations of Euler's tree function (A000169).

Crossrefs

Programs

  • PARI
    {T(n, k)=local(F=x,
    LW=serreverse(x*exp(-x+x*O(x^(n+2)))), M, N, P, m=max(n, k));
    M=matrix(m+3, m+3, r, c, F=x; for(i=1, r+c-2, F=subst(F, x, LW)); polcoeff(F, c));
    N=matrix(m+1, m+1, r, c, M[r, c]);
    P=matrix(m+1, m+1, r, c, M[r+1, c]);
    (n-k)!*(P~*N~^-1)[n+1, k+1]}
    /* Print triangle : */
    for(n=0,10,for(k=0,n,print1(T(n,k),", "));print(""))
    /* Print this sequence, which is central terms */
    for(n=0,20,print1(T(2*n,n),", "))

A274390 Table of coefficients in the iterations of Euler's tree function (A000169), as read by antidiagonals.

Original entry on oeis.org

1, 1, 0, 1, 2, 0, 1, 4, 9, 0, 1, 6, 30, 64, 0, 1, 8, 63, 332, 625, 0, 1, 10, 108, 948, 4880, 7776, 0, 1, 12, 165, 2056, 18645, 89742, 117649, 0, 1, 14, 234, 3800, 50680, 454158, 1986124, 2097152, 0, 1, 16, 315, 6324, 112625, 1537524, 13221075, 51471800, 43046721, 0, 1, 18, 408, 9772, 219000, 4090980, 55494712, 448434136, 1530489744, 1000000000, 0, 1, 20, 513, 14288, 387205, 9266706, 176238685, 2325685632, 17386204761, 51395228090, 25937424601, 0, 1, 22, 630, 20016, 637520, 18704322, 463975764, 8793850560, 111107380464, 759123121050, 1924687118684, 743008370688, 0, 1, 24, 759, 27100, 993105, 34617288, 1067280319, 26858490392, 499217336145, 5964692819140, 36882981687519, 79553145323940, 23298085122481, 0
Offset: 0

Views

Author

Paul D. Hanna, Jun 19 2016

Keywords

Comments

See table A274391 for the coefficients in exp( T^n(x) ), n>=0, where T^n(x) is the e.g.f. of the n-th row of this table.

Examples

			This table begins:
1,  0,   0,     0,       0,        0,          0,            0, ...;
1,  2,   9,    64,     625,     7776,     117649,      2097152, ...;
1,  4,  30,   332,    4880,    89742,    1986124,     51471800, ...;
1,  6,  63,   948,   18645,   454158,   13221075,    448434136, ...;
1,  8, 108,  2056,   50680,  1537524,   55494712,   2325685632, ...;
1, 10, 165,  3800,  112625,  4090980,  176238685,   8793850560, ...;
1, 12, 234,  6324,  219000,  9266706,  463975764,  26858490392, ...;
1, 14, 315,  9772,  387205, 18704322, 1067280319,  70311813880, ...;
1, 16, 408, 14288,  637520, 34617288, 2217367600, 163802295616, ...;
1, 18, 513, 20016,  993105, 59879304, 4254311817, 348285415872, ...;
1, 20, 630, 27100, 1480000, 98110710, 7656893020, 688058734520, ...;
...
where the e.g.f.s of the rows are iterations of T(x) and begin:
T^0(x) = x;
T^1(x) = T(x) = x + 2*x^2/2! + 9*x^3/3! + 64*x^4/4! + 625*x^5/5! + 7776*x^6/6! + 117649*x^7/7! + 2097152*x^8/8! +...+ n^(n-1)*x^n/n! +...;
T^2(x) = T(T(x)) = x + 4*x^2/2! + 30*x^3/3! + 332*x^4/4! + 4880*x^5/5! + 89742*x^6/6! + 1986124*x^7/7! + 51471800*x^8/8! +...+ A207833(n)*x^n/n! +...;
T^3(x) = T(T(T(x))) = x + 6*x^2/2! + 63*x^3/3! + 948*x^4/4! + 18645*x^5/5! + 454158*x^6/6! + 13221075*x^7/7! + 448434136*x^8/8! +...+ A227278(n)*x^n/n! +...;
T^4(x) = T(T(T(T(x)))) = x + 8*x^2/2! + 108*x^3/3! + 2056*x^4/4! + 50680*x^5/5! + 1537524*x^6/6! + 55494712*x^7/7! + 2325685632*x^8/8! +...;
...
where T^n(x)/exp( T^n(x) ) = T^n( x/exp(x) ) = T^(n-1)(x).
Also we have
T(x) = x*exp( T(x) );
T^2(x) = x*exp( T(x) + T^2(x) );
T^3(x) = x*exp( T(x) + T^2(x) + T^3(x) );
T^4(x) = x*exp( T(x) + T^2(x) + T^3(x) + T^4(x) ); ...
		

Crossrefs

Cf. A274570 (transforms diagonals).
Cf. A274740 (same table, but read differently).

Programs

  • PARI
    {ITERATE(F,n,k) = my(G=x +x*O(x^k)); for(i=1,n,G=subst(G,x,F));G}
    {T(n,k) = my(TREE = serreverse(x*exp(-x +x*O(x^k)))); k!*polcoeff(ITERATE(TREE,n,k),k)}
    /* Print this table as a square array */
    for(n=0,10,for(k=1,10,print1(T(n,k),", "));print(""))
    /* Print this table as a flattened array */
    for(n=0,12,for(k=1,n,print1(T(n-k,k),", "));)

Formula

Let T^n(x) denote the n-th iteration of Euler's tree function T(x), then the coefficients in T^n(x) form the n-th row of this table, and the functions satisfy:
(1) T^n(x) = x * exp( Sum_{i=1..n} T^i(x) ).
(2) T^n(x) = T^(n-1)(x) * exp( T^n(x) ).
(3) T^n(x) = T^(n+1)( x/exp(x) ).
Showing 1-5 of 5 results.