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 A060821 Triangle T(n,k) read by rows giving coefficients of Hermite polynomial of order n (n >= 0, 0 <= k <= n). 27
 1, 0, 2, -2, 0, 4, 0, -12, 0, 8, 12, 0, -48, 0, 16, 0, 120, 0, -160, 0, 32, -120, 0, 720, 0, -480, 0, 64, 0, -1680, 0, 3360, 0, -1344, 0, 128, 1680, 0, -13440, 0, 13440, 0, -3584, 0, 256, 0, 30240, 0, -80640, 0, 48384, 0, -9216, 0, 512, -30240, 0, 302400, 0, -403200, 0, 161280, 0, -23040, 0, 1024 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS Exponential Riordan array [exp(-x^2), 2x]. - Paul Barry, Jan 22 2009 LINKS T. D. Noe, Rows n=0..100 of triangle, flattened M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards, Applied Math. Series 55, Tenth Printing, 1972, p. 801. Taekyun Kim, Dae San Kim, A note on Hermite polynomials, arXiv:1602.04096 [math.NT], 2016. Wikipedia, Hermite polynomials FORMULA T(n, k) = ((-1)^((n-k)/2))*(2^k)*n!/(k!*((n-k)/2)!) if n-k is even and >= 0, else 0. E.g.f.: exp(-y^2 + 2*y*x). From Paul Barry, Aug 28 2005: (Start) T(n, k) = n!/(k!*2^((n-k)/2)((n-k)/2)!)2^((n+k)/2)cos(Pi*(n-k)/2)(1 + (-1)^(n+k))/2; T(n, k) = A001498((n+k)/2, (n-k)/2)*cos(Pi*(n-k)/2)2^((n+k)/2)(1 + (-1)^(n+k))/2. (End) Row sums: A062267. - Derek Orr, Mar 12 2015 a(n*(n+3)/2) = a(A000096(n)) = 2^n. - Derek Orr, Mar 12 2015 Recurrence for fixed n: T(n, k) = -(k+2)*(k+1)/(2*(n-k)) * T(n, k+2), starting with T(n, n) = 2^n. - Ralf Stephan, Mar 26 2016 The m-th row consecutive nonzero entries in increasing order are (-1)^(c/2)*(c+b)!/(c/2)!b!*2^b with c = m, m-2, ..., 0 and b = m-c if m is even and with c = m-1, m-3, ..., 0 with b = m-c if m is odd. For the 10th row starting at a(55) the 6 consecutive nonzero entries in order are -30240,302400,-403200,161280,-23040,1024 given by c = 10,8,6,4,2,0 and b = 0,2,4,6,8,10. - Richard Turk, Aug 20 2017 EXAMPLE [1], [0, 2], [ -2, 0, 4], [0, -12, 0, 8], [12, 0, -48, 0, 16], [0, 120, 0, -160, 0, 32], ... . Thus H_0(x) = 1, H_1(x) = 2*x, H_2(x) = -2 + 4*x^2, H_3(x) = -12*x + 8*x^3, H_4(x) = 12 - 48*x^2 + 16*x^4, ... Triangle starts:      1;      0,     2;     -2,     0,      4;      0,   -12,      0,      8;     12,     0,    -48,      0,      16;      0,   120,      0,   -160,       0,    32;   -120,     0,    720,      0,    -480,     0,     64;      0, -1680,      0,   3360,       0, -1344,      0,   128;   1680,     0, -13440,      0,   13440,     0,  -3584,     0,    256;      0, 30240,      0, -80640,       0, 48384,      0, -9216,      0, 512; -30240,     0, 302400,      0, -403200,     0, 161280,     0, -23040,   0, 1024; MAPLE with(orthopoly):for n from 0 to 10 do H(n, x):od; T := proc(n, m) if n-m >= 0 and n-m mod 2 = 0 then ((-1)^((n-m)/2))*(2^m)*n!/(m!*((n-m)/2)!) else 0 fi; end; MATHEMATICA Flatten[ Table[ CoefficientList[ HermiteH[n, x], x], {n, 0, 10}]] (* Jean-François Alcover, Jan 18 2012 *) PROG (PARI) for(n=0, 9, v=Vec(polhermite(n)); forstep(i=n+1, 1, -1, print1(v[i]", "))) \\ Charles R Greathouse IV, Jun 20 2012 (Python) from sympy import hermite, Poly def a(n): return Poly(hermite(n, x), x).all_coeffs()[::-1] for n in xrange(0, 21): print a(n) # Indranil Ghosh, May 26 2017 CROSSREFS Cf. A001814, A001816, A000321, A062267 (row sums). Without initial zeros, same as A059343. Sequence in context: A138090 A138093 A138094 * A191718 A286777 A286123 Adjacent sequences:  A060818 A060819 A060820 * A060822 A060823 A060824 KEYWORD sign,tabl,nice AUTHOR Vladeta Jovovic, Apr 30 2001 STATUS approved

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Last modified October 14 12:02 EDT 2019. Contains 328004 sequences. (Running on oeis4.)