A213500
Rectangular array T(n,k): (row n) = b**c, where b(h) = h, c(h) = h + n - 1, n >= 1, h >= 1, and ** = convolution.
Original entry on oeis.org
1, 4, 2, 10, 7, 3, 20, 16, 10, 4, 35, 30, 22, 13, 5, 56, 50, 40, 28, 16, 6, 84, 77, 65, 50, 34, 19, 7, 120, 112, 98, 80, 60, 40, 22, 8, 165, 156, 140, 119, 95, 70, 46, 25, 9, 220, 210, 192, 168, 140, 110, 80, 52, 28, 10, 286, 275, 255, 228, 196, 161, 125, 90
Offset: 1
Northwest corner (the array is read by southwest falling antidiagonals):
1, 4, 10, 20, 35, 56, 84, ...
2, 7, 16, 30, 50, 77, 112, ...
3, 10, 22, 40, 65, 98, 140, ...
4, 13, 28, 50, 80, 119, 168, ...
5, 16, 34, 60, 95, 140, 196, ...
6, 19, 40, 70, 110, 161, 224, ...
T(6,1) = (1)**(6) = 6;
T(6,2) = (1,2)**(6,7) = 1*7+2*6 = 19;
T(6,3) = (1,2,3)**(6,7,8) = 1*8+2*7+3*6 = 40.
-
b[n_] := n; c[n_] := n
t[n_, k_] := Sum[b[k - i] c[n + i], {i, 0, k - 1}]
TableForm[Table[t[n, k], {n, 1, 10}, {k, 1, 10}]]
Flatten[Table[t[n - k + 1, k], {n, 12}, {k, n, 1, -1}]]
r[n_] := Table[t[n, k], {k, 1, 60}] (* A213500 *)
-
t(n,k) = sum(i=0, k - 1, (k - i) * (n + i));
tabl(nn) = {for(n=1, nn, for(k=1, n, print1(t(k,n - k + 1),", ");); print(););};
tabl(12) \\ Indranil Ghosh, Mar 26 2017
-
def t(n, k): return sum((k - i) * (n + i) for i in range(k))
for n in range(1, 13):
print([t(k, n - k + 1) for k in range(1, n + 1)]) # Indranil Ghosh, Mar 26 2017
A213752
Rectangular array: (row n) = b**c, where b(h) = 2*h-1, c(h) = b(n-1+h), n>=1, h>=1, and ** = convolution.
Original entry on oeis.org
1, 6, 3, 19, 14, 5, 44, 37, 22, 7, 85, 76, 55, 30, 9, 146, 135, 108, 73, 38, 11, 231, 218, 185, 140, 91, 46, 13, 344, 329, 290, 235, 172, 109, 54, 15, 489, 472, 427, 362, 285, 204, 127, 62, 17, 670, 651, 600, 525, 434, 335, 236, 145, 70, 19, 891, 870, 813
Offset: 1
Northwest corner (the array is read by falling antidiagonals):
1...6....19...44....85....146
3...14...37...76....135...218
5...22...55...108...185...290
7...30...73...140...235...362
9...38...91...172...285...434
-
b[n_] := 2 n - 1; c[n_] := 2 n - 1;
t[n_, k_] := Sum[b[k - i] c[n + i], {i, 0, k - 1}]
TableForm[Table[t[n, k], {n, 1, 10}, {k, 1, 10}]]
Flatten[Table[t[n - k + 1, k], {n, 12}, {k, n, 1, -1}]]
r[n_] := Table[t[n, k], {k, 1, 60}] (* A213752 *)
Table[t[n, n], {n, 1, 40}] (* A100157 *)
s[n_] := Sum[t[i, n + 1 - i], {i, 1, n}]
Table[s[n], {n, 1, 50}] (* A071238 *)
A071245
a(n) = n*(n-1)*(2*n^2 + 1)/6.
Original entry on oeis.org
0, 0, 3, 19, 66, 170, 365, 693, 1204, 1956, 3015, 4455, 6358, 8814, 11921, 15785, 20520, 26248, 33099, 41211, 50730, 61810, 74613, 89309, 106076, 125100, 146575, 170703, 197694, 227766, 261145, 298065, 338768, 383504, 432531, 486115, 544530, 608058
Offset: 0
- T. A. Gulliver, Sequences from Arrays of Integers, Int. Math. Journal, Vol. 1, No. 4, pp. 323-332, 2002.
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[n*(n-1)*(2*n^2+1)/6: n in [0..40]]; // Vincenzo Librandi, Jun 14 2011
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Table[n (n - 1) (2 n^2 + 1)/6, {n, 0, 37}] (* or *)
CoefficientList[Series[(-3 x^2 - 4 x^3 - x^4)/(-1 + x)^5, {x, 0, 37}], x] (* Michael De Vlieger, Sep 14 2016 *)
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a(n)=n*(n-1)*(2*n^2+1)/6; \\ Joerg Arndt, Sep 04 2013
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def A071245(n): return binomial(n,2)*(2*n^2+1)//3
[A071245(n) for n in range(41)] # G. C. Greubel, Aug 07 2024
A213836
Rectangular array: (row n) = b**c, where b(h) = 4*h-3, c(h) = n-1+h, n>=1, h>=1, and ** = convolution.
Original entry on oeis.org
1, 7, 2, 22, 13, 3, 50, 37, 19, 4, 95, 78, 52, 25, 5, 161, 140, 106, 67, 31, 6, 252, 227, 185, 134, 82, 37, 7, 372, 343, 293, 230, 162, 97, 43, 8, 525, 492, 434, 359, 275, 190, 112, 49, 9, 715, 678, 612, 525, 425, 320, 218, 127
Offset: 1
Northwest corner (the array is read by falling antidiagonals):
1...7....22...50....95
2...13...37...78....140
3...19...52...106...185
4...25...67...134...230
5...31...82...162...275
6...37...97...190...320
-
b[n_]:=4n-3;c[n_]:=n;
t[n_,k_]:=Sum[b[k-i]c[n+i],{i,0,k-1}]
TableForm[Table[t[n,k],{n,1,10},{k,1,10}]]
Flatten[Table[t[n-k+1,k],{n,12},{k,n,1,-1}]]
r[n_]:=Table[t[n,k],{k,1,60}] (* A213836 *)
Table[t[n,n],{n,1,40}] (* A213837 *)
s[n_]:=Sum[t[i,n+1-i],{i,1,n}]
Table[s[n],{n,1,50}] (* A071238 *)
A071270
a(n) = n^2*(2*n^2 + 1)/3.
Original entry on oeis.org
0, 1, 12, 57, 176, 425, 876, 1617, 2752, 4401, 6700, 9801, 13872, 19097, 25676, 33825, 43776, 55777, 70092, 87001, 106800, 129801, 156332, 186737, 221376, 260625, 304876, 354537, 410032, 471801, 540300, 616001, 699392, 790977, 891276, 1000825, 1120176
Offset: 0
- T. A. Gulliver, Sequences from Arrays of Integers, Int. Math. Journal, Vol. 1, No. 4, pp. 323-332, 2002.
-
[n^2*(2*n^2+1)/3: n in [0..40]]; // Vincenzo Librandi, Jun 14 2011
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A071270:=n->(n^2)*(2*n^2+1)/3; seq(A071270(n), n=0..100); # Wesley Ivan Hurt, Nov 14 2013
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Table[(n^2)(2n^2+1)/3, {n,0,100}] (* Wesley Ivan Hurt, Nov 14 2013 *)
LinearRecurrence[{5,-10,10,-5,1},{0,1,12,57,176},50] (* Harvey P. Dale, Jan 09 2016 *)
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a <- c(0, 1, 12, 57, 176)
for(n in (length(a)+1):30)
a[n] <- 5*a[n-1]-10*a[n-2]+10*a[n-3]-5*a[n-4]+a[n-5]
a # Yosu Yurramendi, Sep 03 2013
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def A071270(n): return binomial(2*n^2 + 1,2)/3
[A071270(n) for n in range(41)] # G. C. Greubel, Sep 13 2024
A277229
Convolution of the odd-indexed triangular numbers (A000384(n+1)) and the squares (A000290).
Original entry on oeis.org
0, 1, 10, 48, 158, 413, 924, 1848, 3396, 5841, 9526, 14872, 22386, 32669, 46424, 64464, 87720, 117249, 154242, 200032, 256102, 324093, 405812, 503240, 618540, 754065, 912366, 1096200, 1308538, 1552573, 1831728, 2149664, 2510288, 2917761, 3376506, 3891216
Offset: 0
-
Table[n (n + 1) (n + 2) (4 n^2 + 3 n + 3)/60, {n, 0, 40}] (* Bruno Berselli, Oct 21 2016 *)
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concat(0, Vec(x*((1+x)*(1+3*x))/(1-x)^6 + O(x^50))) \\ Colin Barker, Oct 21 2016
Showing 1-6 of 6 results.
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