This site is supported by donations to The OEIS Foundation.

 Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing. Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A166318 Exponential Riordan array [sech(2x), arctan(tanh(x))]. 1
 1, 0, 1, -4, 0, 1, 0, -16, 0, 1, 80, 0, -40, 0, 1, 0, 640, 0, -80, 0, 1, -3904, 0, 2800, 0, -140, 0, 1, 0, -49152, 0, 8960, 0, -224, 0, 1, 354560, 0, -319744, 0, 23520, 0, -336, 0, 1, 0, 6225920, 0, -1454080, 0, 53760, 0, -480, 0, 1, -51733504, 0, 54897920, 0 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 0,4 COMMENTS Inverse is A166317. Row sums are A012222(n+1). Signed version of A166317. Also the Bell transform of the sequence a(n) = 2^n*E(n) (E(n) the Euler numbers) without column 0. For the definition of the Bell transform see A264428. - Peter Luschny, Jan 29 2016 LINKS EXAMPLE Triangle begins 1, 0, 1, -4, 0, 1, 0, -16, 0, 1, 80, 0, -40, 0, 1, 0, 640, 0, -80, 0, 1, -3904, 0, 2800, 0, -140, 0, 1, 0, -49152, 0, 8960, 0, -224, 0, 1, 354560, 0, -319744, 0, 23520, 0, -336, 0, 1, 0, 6225920, 0, -1454080, 0, 53760, 0, -480, 0, 1, Production matrix is 0, 1, -4, 0, 1, 0, -12, 0, 1, 16, 0, -24, 0, 1, 0, 80, 0, -40, 0, 1, -64, 0, 240, 0, -60, 0, 1, 0, -448, 0, 560, 0, -84, 0, 1, 256, 0, -1792, 0, 1120, 0, -112, 0, 1, 0, 2304, 0, -5376, 0, 2016, 0, -144, 0, 1, -1024, 0, 11520, 0, -13440, 0, 3360, 0, -180, 0, 1 which is the exponential Riordan array [cos(2x),x] minus its top row. MAPLE # The function BellMatrix is defined in A264428. # Adds (1, 0, 0, 0, ..) as column 0. BellMatrix(n -> 2^n*euler(n), 10); # Peter Luschny, Jan 29 2016 MATHEMATICA BellMatrix[f_, len_] := With[{t = Array[f, len, 0]}, Table[BellY[n, k, t], {n, 0, len - 1}, {k, 0, len - 1}]]; B = BellMatrix[Function[n, 2^n EulerE[n]], rows = 12]; Table[B[[n, k]], {n, 2, rows}, {k, 2, n}] // Flatten (* Jean-François Alcover, Jun 28 2018, after Peter Luschny *) CROSSREFS Sequence in context: A268367 A117436 A136448 * A166317 A068346 A006838 Adjacent sequences:  A166315 A166316 A166317 * A166319 A166320 A166321 KEYWORD easy,sign,tabl AUTHOR Paul Barry, Oct 11 2009 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 7 05:14 EST 2019. Contains 329839 sequences. (Running on oeis4.)