A027472
Third convolution of the powers of 3 (A000244).
Original entry on oeis.org
1, 9, 54, 270, 1215, 5103, 20412, 78732, 295245, 1082565, 3897234, 13817466, 48361131, 167403915, 573956280, 1951451352, 6586148313, 22082967873, 73609892910, 244074908070, 805447196631, 2646469360359, 8661172452084, 28242953648100, 91789599356325, 297398301914493, 960825283108362, 3095992578904722
Offset: 3
Sequences similar to the form q^(n-2)*binomial(n, 2):
A000217 (q=1),
A001788 (q=2), this sequence (q=3),
A038845 (q=4),
A081135 (q=5),
A081136 (q=6),
A027474 (q=7),
A081138 (q=8),
A081139 (q=9),
A081140 (q=10),
A081141 (q=11),
A081142 (q=12),
A027476 (q=15).
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[3^(n-3)*Binomial(n-1, 2): n in [3..40]]; // G. C. Greubel, May 12 2021
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nn=41; Drop[Range[0,nn]!CoefficientList[Series[Exp[x]^3 x^2/2!,{x,0,nn}],x],2] (* Geoffrey Critzer, Oct 03 2013 *)
LinearRecurrence[{9,-27,27}, {1,9,54}, 40] (* G. C. Greubel, May 12 2021 *)
Abs[Take[CoefficientList[Series[1/(1+3x^2)^3,{x,0,60}],x],{1,-1,2}]] (* Harvey P. Dale, Mar 03 2022 *)
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a(n)=([0,1,0; 0,0,1; 27,-27,9]^(n-3)*[1;9;54])[1,1] \\ Charles R Greathouse IV, Oct 03 2016
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[3^(n-3)*binomial(n-1,2) for n in range(3, 40)] # Zerinvary Lajos, Mar 10 2009
A036216
Expansion of 1/(1 - 3*x)^4; 4-fold convolution of A000244 (powers of 3).
Original entry on oeis.org
1, 12, 90, 540, 2835, 13608, 61236, 262440, 1082565, 4330260, 16888014, 64481508, 241805655, 892820880, 3252418920, 11708708112, 41712272649, 147219785820, 515269250370, 1789882659180, 6175095174171, 21171754882872
Offset: 0
Sequences of the form 3^n*binomial(n+m, m):
A000244 (m=0),
A027471 (m=1),
A027472 (m=2), this sequence (m=3),
A036217 (m=4),
A036219 (m=5),
A036220 (m=6),
A036221 (m=7),
A036222 (m=8),
A036223 (m=9),
A172362 (m=10).
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[3^n* Binomial(n+3, 3): n in [0..30]]; // Vincenzo Librandi, Oct 14 2011
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seq(3^n*binomial(n+3, 3), n=0..30)]; # Zerinvary Lajos, Dec 21 2006
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CoefficientList[Series[1/(1-3x)^4,{x,0,30}],x] (* or *) LinearRecurrence[ {12,-54,108,-81},{1,12,90,540},30] (* Harvey P. Dale, Jul 27 2017 *)
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a(n) = 3^n*binomial(n+3, 3) \\ Charles R Greathouse IV, Oct 03 2016
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[3^n*binomial(n+3,3) for n in range(30)] # Zerinvary Lajos, Mar 10 2009
A036217
Expansion of 1/(1-3*x)^5; 5-fold convolution of A000244 (powers of 3).
Original entry on oeis.org
1, 15, 135, 945, 5670, 30618, 153090, 721710, 3247695, 14073345, 59108049, 241805655, 967222620, 3794488740, 14635885140, 55616363532, 208561363245, 772903875555, 2833980877035, 10291825290285, 37050571045026
Offset: 0
Sequences of the form 3^n*binomial(n+m, m):
A000244 (m=0),
A027471 (m=1),
A027472 (m=2),
A036216 (m=3), this sequence (m=4),
A036219 (m=5),
A036220 (m=6),
A036221 (m=7),
A036222 (m=8),
A036223 (m=9),
A172362 (m=10).
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[3^n* Binomial(n+4, 4): n in [0..30]]; // Vincenzo Librandi, Oct 14 2011
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seq(3^n*binomial(n+4,4), n=0..30); # Zerinvary Lajos, Jun 12 2008
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CoefficientList[Series[1/(1-3x)^5,{x,0,30}],x] (* Harvey P. Dale, Jun 13 2017 *)
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[3^n*binomial(n+4,4) for n in range(30)] # Zerinvary Lajos, Mar 10 2009
A036219
Expansion of 1/(1-3*x)^6; 6-fold convolution of A000244 (powers of 3).
Original entry on oeis.org
1, 18, 189, 1512, 10206, 61236, 336798, 1732104, 8444007, 39405366, 177324147, 773778096, 3288556908, 13660159464, 55616363532, 222465454128, 875957725629, 3400777052442, 13036312034361, 49400761393368, 185252855225130, 688082033693340, 2533392942234570
Offset: 0
Sequences of the form 3^n*binomial(n+m, m):
A000244 (m=0),
A027471 (m=1),
A027472 (m=2),
A036216 (m=3),
A036217 (m=4), this sequence (m=5),
A036220 (m=6),
A036221 (m=7),
A036222 (m=8),
A036223 (m=9),
A172362 (m=10).
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[3^n*Binomial(n+5, 5): n in [0..30]]; // Vincenzo Librandi, Oct 15 2011
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seq(3^n*binomial(n+5,5), n=0..30); # Zerinvary Lajos, Jun 13 2008
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Table[3^n*Binomial[n+5, 5], {n, 0, 30}] (* G. C. Greubel, May 19 2021 *)
CoefficientList[Series[1/(1-3x)^6,{x,0,30}],x] (* or *) LinearRecurrence[ {18,-135,540,-1215,1458,-729},{1,18,189,1512,10206,61236},30] (* Harvey P. Dale, Jan 02 2022 *)
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[3^n*binomial(n+5,5) for n in range(30)] # Zerinvary Lajos, Mar 10 2009
A036220
Expansion of 1/(1-3*x)^7; 7-fold convolution of A000244 (powers of 3).
Original entry on oeis.org
1, 21, 252, 2268, 17010, 112266, 673596, 3752892, 19702683, 98513415, 472864392, 2192371272, 9865670724, 43257171636, 185387878440, 778629089448, 3211844993973, 13036312034361, 52145248137444, 205836505805700, 802762372642230, 3096369151620030
Offset: 0
Sequences of the form 3^n*binomial(n+m, m):
A000244 (m=0),
A027471 (m=1),
A027472 (m=2),
A036216 (m=3),
A036217 (m=4),
A036219 (m=5), this sequence (m=6),
A036221 (m=7),
A036222 (m=8),
A036223 (m=9),
A172362 (m=10).
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[3^n*Binomial(n+6, 6): n in [0..30]]; // Vincenzo Librandi, Oct 15 2011
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seq(3^n*binomial(n+6,6), n=0..20); # Zerinvary Lajos, Jun 16 2008
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Table[3^n*Binomial[n+6, 6], {n,0,30}] (* G. C. Greubel, May 19 2021 *)
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[3^n*binomial(n+6,6) for n in range(30)] # Zerinvary Lajos, Mar 10 2009
A036221
Expansion of 1/(1-3*x)^8; 8-fold convolution of A000244 (powers of 3).
Original entry on oeis.org
1, 24, 324, 3240, 26730, 192456, 1250964, 7505784, 42220035, 225173520, 1148384952, 5637526128, 26778249108, 123591918960, 556163635320, 2447119995408, 10553204980197, 44695926974952, 186233029062300
Offset: 0
- Vincenzo Librandi, Table of n, a(n) for n = 0..400
- Index entries for linear recurrences with constant coefficients, signature (24,-252,1512,-5670,13608,-20412,17496,-6561).
Sequences of the form 3^n*binomial(n+m, m):
A000244 (m=0),
A027471 (m=1),
A027472 (m=2),
A036216 (m=3),
A036217 (m=4),
A036219 (m=5),
A036220 (m=6), this sequence (m=7),
A036222 (m=8),
A036223 (m=9),
A172362 (m=10).
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[3^n*Binomial(n+7, 7): n in [0..30]]; // Vincenzo Librandi, Oct 15 2011
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seq(3^n*binomial(n+7,7), n=0..30); # Zerinvary Lajos, Jun 23 2008
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Table[3^n*Binomial[n+7,7], {n,0,30}] (* G. C. Greubel, May 19 2021 *)
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[3^n*binomial(n+7, 7) for n in range(30)] # Zerinvary Lajos, Mar 13 2009
A036222
Expansion of 1/(1-3*x)^9; 9-fold convolution of A000244 (powers of 3).
Original entry on oeis.org
1, 27, 405, 4455, 40095, 312741, 2189187, 14073345, 84440070, 478493730, 2583866142, 13389124554, 66945622770, 324428787270, 1529449997130, 7035469986798, 31659614940591, 139674771796725, 605257344452475
Offset: 0
- Vincenzo Librandi, Table of n, a(n) for n = 0..400
- Index entries for linear recurrences with constant coefficients, signature (27,-324,2268,-10206,30618,-61236,78732,-59049,19683).
Sequences of the form 3^n*binomial(n+m, m):
A000244 (m=0),
A027471 (m=1),
A027472 (m=2),
A036216 (m=3),
A036217 (m=4),
A036219 (m=5),
A036220 (m=6),
A036221 (m=7), this sequence (m=8),
A036223 (m=9),
A172362 (m=10).
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[3^n*Binomial(n+8, 8): n in [0..30]]; // Vincenzo Librandi, Oct 15 2011
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seq(3^n*binomial(n+8,8), n=0..18); # Zerinvary Lajos, Jun 23 2008
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Table[3^n*Binomial[n+8, 8], {n, 0, 20}] (* Zerinvary Lajos, Jan 31 2010 *)
CoefficientList[Series[1/(1-3x)^9,{x,0,30}],x] (* or *) LinearRecurrence[{27,-324, 2268,-10206,30618,-61236,78732,-59049,19683}, {1,27,405,4455,40095,312741, 2189187,14073345,84440070}, 30] (* Harvey P. Dale, Jan 07 2016 *)
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[3^n*binomial(n+8, 8) for n in range(30)] # Zerinvary Lajos, Mar 13 2009
A036223
Expansion of 1/(1-3*x)^10; 10-fold convolution of A000244 (powers of 3).
Original entry on oeis.org
1, 30, 495, 5940, 57915, 486486, 3648645, 25019280, 159497910, 956987460, 5454828522, 29753610120, 156206453130, 793048146660, 3908594437110, 18761253298128, 87943374834975, 403504896301650, 1815772033357425
Offset: 0
- Vincenzo Librandi, Table of n, a(n) for n = 0..400
- Index entries for linear recurrences with constant coefficients, signature (30,-405,3240,-17010,61236,-153090,262440,-295245,196830,-59049).
Sequences of the form 3^n*binomial(n+m, m):
A000244 (m=0),
A027471 (m=1),
A027472 (m=2),
A036216 (m=3),
A036217 (m=4),
A036219 (m=5),
A036220 (m=6),
A036221 (m=7),
A036222 (m=8), this sequence (m=9),
A172362 (m=10).
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[3^n*Binomial(n+9, 9): n in [0..30]]; // Vincenzo Librandi, Oct 15 2011
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seq(3^n*binomial(n+9, 9), n=0..20); # Zerinvary Lajos, Jul 02 2008
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Table[3^n*Binomial[n+9,9], {n,0,30}] (* G. C. Greubel, May 18 2021 *)
CoefficientList[Series[1/(1-3x)^10,{x,0,30}],x] (* or *) LinearRecurrence[ {30,-405,3240,-17010,61236,-153090,262440,-295245,196830,-59049},{1,30,495,5940,57915,486486,3648645,25019280,159497910,956987460},30] (* Harvey P. Dale, Jan 16 2022 *)
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[3^n*binomial(n+9,9) for n in range(30)] # Zerinvary Lajos, Mar 13 2009
A074472
Length of iteration sequence of Collatz-function (A006370) when initial value is 3^n (A000244) and final cycle is followed once.
Original entry on oeis.org
1, 8, 20, 112, 23, 97, 34, 77, 76, 44, 136, 135, 134, 133, 145, 206, 130, 191, 141, 96, 95, 262, 429, 92, 259, 395, 332, 256, 255, 391, 390, 389, 463, 462, 461, 460, 459, 458, 457, 456, 455, 454, 502, 501, 451, 499, 498, 753, 496, 495, 494, 749, 492, 747, 490
Offset: 0
n=2: initial value=3^2, list of iterates is {9,28,14,7,22,11,34,17,52,26,13,50,20,10,5,16,8,4,2,1} length=a(2)=20; Observe that consecutive powers of 3 as arguments frequently provide iteration-lengths of consecutive integers, for instance n=10,11,12,13 give L=136,135,134,133 or n=88-96 result in L=1278-1271.
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f[x_] := (1-Mod[x, 2])*(x/2)+(Mod[x, 2])*(3*x+1); f[1]=1; Table[1+Length[FixedPointList[f, 3^w]], {w, 1, 100}]
A037095
"Sloping binary representation" of powers of 3 (A000244), slope = -1.
Original entry on oeis.org
1, 1, 3, 1, 3, 9, 11, 17, 19, 25, 123, 65, 195, 169, 171, 753, 435, 249, 2267, 4065, 8163, 841, 843, 31313, 29651, 39769, 38331, 30081, 160643, 49769, 53867, 563377, 700659, 1611961, 760731, 1207073, 5668771, 5566345, 11844619, 8699025, 10386067, 55868313
Offset: 0
When powers of 3 are written in binary (see A004656), under each other as:
000000000001 (1)
000000000011 (3)
000000001001 (9)
000000011011 (27)
000001010001 (81)
000011110011 (243)
001011011001 (729)
100010001011 (2187)
and one collects their bits from the column-0 to NW-direction (from the least to the most significant end), one gets 1 (1), 01 (1), 011 (3), 0001 (1), 00011 (3), 001001 (9), etc. (See A105033 for similar transformation done on nonnegative integers, A001477).
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A037095:= n-> add(bit_n(3^(n-i), i)*(2^i), i=0..n):
bit_n := (x, n) -> `mod`(floor(x/(2^n)), 2):
seq(A037095(n), n=0..41);
# second Maple program:
b:= proc(n) option remember; `if`(n=0, 1, (p->
expand((p-(p mod 2))*x/2)+3^n)(b(n-1)))
end:
a:= n-> subs(x=2, b(n) mod 2):
seq(a(n), n=0..42); # Alois P. Heinz, Dec 10 2020
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A339601(n) = { my(m=1, s=0); while(n>=m, s += bitand(m,n); m <<= 1; n \= 3); (s); };
A037095(n) = A339601(3^n); \\ Antti Karttunen, Dec 09 2020
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BINSLOPE(f) = n -> sum(i=0,n,bitand(2^(n-i),f(i))); \\ General transformation for these kinds of sequences.
A037095 = BINSLOPE(n -> 3^n); \\ And its application to A000244. - Antti Karttunen, Dec 09 2020
Entry revised Dec 29 2007
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