A135950 Matrix inverse of triangle A022166.

1, -1, 1, 2, -3, 1, -8, 14, -7, 1, 64, -120, 70, -15, 1, -1024, 1984, -1240, 310, -31, 1, 32768, -64512, 41664, -11160, 1302, -63, 1, -2097152, 4161536, -2731008, 755904, -94488, 5334, -127, 1, 268435456, -534773760, 353730560, -99486720, 12850368, -777240, 21590, -255, 1

Offset

0,4

Comments

A022166 is the triangle of Gaussian binomial coefficients [n,k] for q = 2.

The coefficient [x^k] of Product_{i=1..n} (x-2^(i-1)). - Roger L. Bagula, Mar 20 2009

Triangle T(n,k), 0 <= k <= n, read by rows given by (-1, 1-q, -q^2, q-q^3, -q^4, q^2-q^5, -q^6, q^3-q^7, -q^8, ...) DELTA (1, 0, q, 0, q^2, 0, q^3, 0, q^4, 0, ...) (for q = 2) = (-1, -1, -4, -6, -16, -28, -64, -120, -256, ...) DELTA (1, 0, 2, 0, 4, 0, 8, 0, 16, 0, ...) where DELTA is the operator defined in A084938. - Philippe Deléham, Oct 20 2013

Reversed rows of triangle A158474. - Werner Schulte, Apr 06 2019

Links

G. C. Greubel, Rows n = 0..75 of triangle, flattened

Formula

Unsigned column 0 equals A006125(n) = 2^(n*(n-1)/2). Unsigned column 1 equals A127850(n) = (2^n-1)*2^(n*(n-1)/2)/2^(n-1). Row sums equal 0^n. Unsigned row sums equal A028361(n) = Product_{k=0..n} (1+2^k).

T(n,k) = (-1)^(n-k) * A022166(n,k) * 2^binomial(n-k,2) for 0 <= k <= n. - Werner Schulte, Apr 06 2019 [corrected by Werner Schulte, Dec 27 2021]

Example

Triangle begins:
         1;
        -1,       1;
         2,      -3,        1;
        -8,      14,       -7,      1;
        64,    -120,       70,    -15,      1;
     -1024,    1984,    -1240,    310,    -31,    1;
     32768,  -64512,    41664, -11160,   1302,  -63,    1;
  -2097152, 4161536, -2731008, 755904, -94488, 5334, -127, 1; ...

Mathematica

max = 9; M = Table[QBinomial[n, k, 2], {n, 0, max}, {k, 0, max}] // Inverse; Table[M[[n, k]], {n, 1, max+1}, {k, 1, n}] // Flatten (* Jean-François Alcover, Apr 08 2016 *)
p[x_, n_, q_] := (-1)^n*q^Binomial[n, 2]*QPochhammer[x, 1/q, n];
Table[CoefficientList[Series[p[x, n, 2], {x, 0, n}], x], {n, 0, 10}]// Flatten (* G. C. Greubel, Apr 15 2019 *)

Prog

(PARI) T(n, k)=local(q=2, A=matrix(n+1, n+1, n, k, if(n>=k, if(n==1 || k==1, 1, prod(j=n-k+1, n-1, 1-q^j)/prod(j=1, k-1, 1-q^j))))^-1); A[n+1, k+1]

Crossrefs

Cf. A022166, A006125, A028361, A127850, A135951 (central terms), A158474.

Sequence in context: A098435 A096294 A157963 * A202063 A200016 A147557

Adjacent sequences: A135947 A135948 A135949 * A135951 A135952 A135953

Keyword

sign,tabl

Author

Paul D. Hanna, Dec 08 2007

Status

approved