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A038231 Triangle whose (i,j)-th entry is binomial(i,j)*4^(i-j). 18

%I

%S 1,4,1,16,8,1,64,48,12,1,256,256,96,16,1,1024,1280,640,160,20,1,4096,

%T 6144,3840,1280,240,24,1,16384,28672,21504,8960,2240,336,28,1,65536,

%U 131072,114688,57344,17920,3584,448,32,1,262144,589824,589824,344064,129024,32256,5376,576,36,1

%N Triangle whose (i,j)-th entry is binomial(i,j)*4^(i-j).

%C Triangle of coefficients in expansion of (4+x)^n. - _N-E. Fahssi_, Apr 13 2008

%H Indranil Ghosh, <a href="/A038231/b038231.txt">Rows 0..125 of triangle, flattened</a>

%H Naiomi T. Cameron and Asamoah Nkwanta, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL8/Cameron/cameron46.html">On Some (Pseudo) Involutions in the Riordan Group</a>, Journal of Integer Sequences, Vol. 8 (2005), Article 05.3.7.

%H B. N. Cyvin et al., <a href="http://match.pmf.kg.ac.rs/electronic_versions/Match34/match34_109-121.pdf">Isomer enumeration of unbranched catacondensed polygonal systems with pentagons and heptagons</a>, Match, No. 34 (Oct 1996), pp. 109-121.

%F G.f. for j-th column is (x^j)/(1-4*x)^(j+1).

%F Convolution triangle of A000302 (powers of 4).

%F Sum_{k=0..n} T(n,k)*(-1)^k*A000108(k) = A001700(n). - _Philippe Deléham_, Nov 27 2009

%F See A038207 and A027465 and replace 2 and 3 in analogous formulas with 4. - _Tom Copeland_, Oct 26 2012

%e Triangle begins:

%e 1;

%e 4, 1;

%e 16, 8, 1;

%e 64, 48, 12, 1;

%e 256, 256, 96, 16, 1;

%e 1024, 1280, 640, 160, 20, 1;

%e 4096, 6144, 3840, 1280, 240, 24, 1;

%e 16384, 28672, 21504, 8960, 2240, 336, 28, 1;

%e 65536, 131072, 114688, 57344, 17920, 3584, 448, 32, 1;

%p for i from 0 to 10 do seq(binomial(i, j)*4^(i-j), j = 0 .. i) od; # _Zerinvary Lajos_, Dec 21 2007

%t Table[4^(n-k)*Binomial[n, k], {n,0,10}, {k,0,n}]//Flatten (* _G. C. Greubel_, Jul 20 2019 *)

%o (PARI) T(n,k) = 4^(n-k)*binomial(n, k); \\ _G. C. Greubel_, Jul 20 2019

%o (MAGMA) [4^(n-k)*Binomial(n, k): k in [0..n], n in [0..10]]; // _G. C. Greubel_, Jul 20 2019

%o (Sage) [[4^(n-k)*binomial(n, k) for k in (0..n)] for n in (0..10)] # _G. C. Greubel_, Jul 20 2019

%o (GAP) Flat(List([0..10], n-> List([0..n], k-> 4^(n-k)*Binomial(n, k) ))); # _G. C. Greubel_, Jul 20 2019

%Y Cf. A013611 (row-reversed), A000351 (row sums).

%K nonn,tabl,easy,changed

%O 0,2

%A _N. J. A. Sloane_

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Last modified September 28 13:24 EDT 2020. Contains 337393 sequences. (Running on oeis4.)