1, 1, 0, 2, 1, 0, 4, 3, 0, 0, 8, 8, 1, 0, 0, 16, 20, 5, 0, 0, 0, 32, 48, 18, 1, 0, 0, 0, 64, 112, 56, 7, 0, 0, 0, 0, 128, 256, 160, 32, 1, 0, 0, 0, 0, 256, 576, 432, 120, 9, 0, 0, 0, 0, 0, 512, 1280, 1120, 400, 50, 1, 0, 0, 0, 0, 0
Offset: 0
A202064
Triangle T(n,k), read by rows, given by (2, -1/2, 1/2, 0, 0, 0, 0, 0, 0, 0, ...) DELTA (0, 1/2, -1/2, 0, 0, 0, 0, 0, 0, 0, ...) where DELTA is the operator defined in A084938.
Original entry on oeis.org
1, 2, 0, 3, 1, 0, 4, 4, 0, 0, 5, 10, 1, 0, 0, 6, 20, 6, 0, 0, 0, 7, 35, 21, 1, 0, 0, 0, 8, 56, 56, 8, 0, 0, 0, 0, 9, 84, 126, 36, 1, 0, 0, 0, 0, 10, 120, 252, 120, 10, 0, 0, 0, 0, 0, 11, 165, 462, 330, 55, 1, 0, 0, 0, 0, 0
Offset: 0
Triangle begins :
1
2, 0
3, 1, 0
4, 4, 0, 0
5, 10, 1, 0, 0
6, 20, 6, 0, 0, 0
7, 35, 21, 1, 0, 0, 0
8, 56, 56, 8, 0, 0, 0, 0
Last nonzero term in each row appears to be
A124625.
A034839 counts subsets by number of maximal runs, for anti-runs
A384893.
A116674 counts strict partitions by number of maximal runs, for anti-runs
A384905.
Cf.
A000045,
A000071,
A001629,
A010027,
A053538,
A208342,
A210034,
A245563,
A268193,
A384177,
A384890.
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Table[Length[Select[Subsets[Range[n]],MemberQ[#,n]&&Length[Split[#,#2==#1+1&]]==k&]],{n,12},{k,n}] (* Gus Wiseman, Jul 07 2025 *)
A133345
a(n) = 2*a(n-1) + 14*a(n-2) for n>1, a(0)=1, a(1)=1.
Original entry on oeis.org
1, 1, 16, 46, 316, 1276, 6976, 31816, 161296, 768016, 3794176, 18340576, 89799616, 436367296, 2129929216, 10369000576, 50557010176, 246280028416, 1200358199296, 5848636796416, 28502288382976, 138885491915776
Offset: 0
-
[n le 2 select 1 else 2*(Self(n-1) +7*Self(n-2)): n in [1..41]]; // G. C. Greubel, Oct 15 2022
-
LinearRecurrence[{2,14},{1,1},30] (* Harvey P. Dale, Jan 07 2016 *)
-
Vec((1-x)/(1-2*x-14*x^2)+O(x^99)) \\ Charles R Greathouse IV, Jan 12 2012
-
A133345=BinaryRecurrenceSequence(2,14,1,1)
[A133345(n) for n in range(41)] # G. C. Greubel, Oct 15 2022
A133356
a(n) = 2*a(n-1) + 16*a(n-2) for n>1, a(0)=1, a(1)=1.
Original entry on oeis.org
1, 1, 18, 52, 392, 1616, 9504, 44864, 241792, 1201408, 6271488, 31765504, 163874816, 835997696, 4293992448, 21963948032, 112631775232, 576686718976, 2955481841664, 15137951186944, 77563611840512, 397334442672128
Offset: 0
-
[n le 2 select 1 else 2*(Self(n-1) +8*Self(n-2)): n in [1..41]]; // G. C. Greubel, Oct 15 2022
-
LinearRecurrence[{2,16},{1,1},30] (* Harvey P. Dale, Dec 12 2012 *)
-
Vec((1-x)/(1-2*x-16*x^2)+O(x^99)) \\ Charles R Greathouse IV, Jan 12 2012
-
A133356=BinaryRecurrenceSequence(2,16,1,1)
[A133356(n) for n in range(41)] # G. C. Greubel, Oct 15 2022
A138229
Expansion of (1-x)/(1-2x+6x^2).
Original entry on oeis.org
1, 1, -4, -14, -4, 76, 176, -104, -1264, -1904, 3776, 18976, 15296, -83264, -258304, -17024, 1515776, 3133696, -2827264, -24456704, -31949824, 82840576, 357380096, 217716736, -1708847104, -4723994624, 805093376
Offset: 0
- Michael De Vlieger, Table of n, a(n) for n = 0..2571
- Beata Bajorska-Harapińska, Barbara Smoleń, Roman Wituła, On Quaternion Equivalents for Quasi-Fibonacci Numbers, Shortly Quaternaccis, Advances in Applied Clifford Algebras (2019) Vol. 29, 54.
- Index entries for linear recurrences with constant coefficients, signature (2,-6).
-
CoefficientList[Series[(1-x)/(1-2x+6x^2),{x,0,30}],x] (* or *) LinearRecurrence[ {2,-6},{1,1},30] (* Harvey P. Dale, Feb 29 2012 *)
TrigExpand@Table[6^(n/2) Cos[n ArcTan[Sqrt[5]]], {n, 0, 20}] (* or *)
Table[Sum[(-5)^k Binomial[n, 2 k], {k, 0, n/2}], {n, 0, 20}] (* Vladimir Reshetnikov, Sep 20 2016 *)
-
[lucas_number2(n,2,6)/2 for n in range(0,28)] # Zerinvary Lajos, Jul 08 2008
A145302
a(n) = ((7 + sqrt(7))^n + (7 - sqrt(7))^n)/2.
Original entry on oeis.org
1, 7, 56, 490, 4508, 42532, 406112, 3899224, 37532432, 361686640, 3487250816, 33630672544, 324364881344, 3128620091968, 30177356271104, 291080943932800, 2807684251672832, 27082179878242048, 261227779725129728
Offset: 0
Al Hakanson (hawkuu(AT)gmail.com), Oct 06 2008
A145303
a(n) = ((8 + sqrt(8))^n + (8 - sqrt(8))^n)/2.
Original entry on oeis.org
1, 8, 72, 704, 7232, 76288, 815616, 8777728, 94769152, 1024753664, 11088986112, 120037572608, 1299617939456, 14071782965248, 152369922834432, 1649898919297024, 17865667030024192, 193456332999753728
Offset: 0
Al Hakanson (hawkuu(AT)gmail.com), Oct 06 2008
A081335
a(n) = (6^n + 2^n)/2.
Original entry on oeis.org
1, 4, 20, 112, 656, 3904, 23360, 140032, 839936, 5039104, 30233600, 181399552, 1088393216, 6530351104, 39182090240, 235092508672, 1410554986496, 8463329787904, 50779978465280, 304679870267392, 1828079220555776
Offset: 0
-
List([0..30], n-> 2^(n-1)*(3^n + 1)); # G. C. Greubel, Aug 02 2019
-
[(6^n+2^n)/2: n in [0..30]]; // Vincenzo Librandi, Aug 08 2013
-
LinearRecurrence[{8, -12}, {1, 4}, 30] (* Harvey P. Dale, May 03 2013 *)
CoefficientList[Series[(1-4x)/((1-2x)(1-6x)), {x,0,30}], x] (* Vincenzo Librandi, Aug 08 2013 *)
-
a(n)=(6^n+2^n)/2 \\ Charles R Greathouse IV, Oct 07 2015
-
[2^(n-1)*(3^n + 1) for n in (0..30)] # G. C. Greubel, Aug 02 2019
A119275
Inverse of triangle related to Padé approximation of exp(x).
Original entry on oeis.org
1, -2, 1, 0, -6, 1, 0, 12, -12, 1, 0, 0, 60, -20, 1, 0, 0, -120, 180, -30, 1, 0, 0, 0, -840, 420, -42, 1, 0, 0, 0, 1680, -3360, 840, -56, 1, 0, 0, 0, 0, 15120, -10080, 1512, -72, 1, 0, 0, 0, 0, -30240, 75600, -25200, 2520, -90, 1, 0, 0, 0, 0, 0, -332640, 277200, -55440, 3960, -110, 1
Offset: 0
Triangle begins
1,
-2, 1,
0, -6, 1,
0, 12, -12, 1,
0, 0, 60, -20, 1,
0, 0, -120, 180, -30, 1,
0, 0, 0, -840, 420, -42, 1,
0, 0, 0, 1680, -3360, 840, -56, 1,
0, 0, 0, 0, 15120, -10080, 1512, -72, 1
Row 4: D(x^4) = (1 - x*(d/dx)^2 + x^2/2!*(d/dx)^4 - ...)(x^4) = x^4 - 12*x^3 + 12*x^2.
Cf.
A059344 (unsigned row reverse).
-
# The function BellMatrix is defined in A264428.
# Adds (1,0,0,0, ..) as column 0.
BellMatrix(n -> `if`(n<2,(n+1)*(-1)^n,0), 9); # Peter Luschny, Jan 27 2016
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Table[(-1)^(n - k) (n - k)!*Binomial[n + 1, k + 1] Binomial[k + 1, n - k], {n, 0, 10}, {k, 0, n}] // Flatten (* Michael De Vlieger, Oct 12 2016 *)
BellMatrix[f_Function, len_] := With[{t = Array[f, len, 0]}, Table[BellY[n, k, t], {n, 0, len - 1}, {k, 0, len - 1}]];
rows = 12;
M = BellMatrix[If[#<2, (#+1) (-1)^#, 0]&, rows];
Table[M[[n, k]], {n, 2, rows}, {k, 2, n}] // Flatten (* Jean-François Alcover, Jun 24 2018, after Peter Luschny *)
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# uses[inverse_bell_matrix from A265605]
# Unsigned values and an additional first column (1,0,0, ...).
multifact_4_2 = lambda n: prod(4*k + 2 for k in (0..n-1))
inverse_bell_matrix(multifact_4_2, 9) # Peter Luschny, Dec 31 2015
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