A006527 -id:A006527 - cp's OEIS frontend

A185878 Accumulation array of A185877, by antidiagonals.

1, 4, 2, 11, 10, 3, 24, 28, 18, 4, 45, 60, 51, 28, 5, 76, 110, 108, 80, 40, 6, 119, 182, 195, 168, 115, 54, 7, 176, 280, 318, 300, 240, 156, 70, 8, 249, 408, 483, 484, 425, 324, 203, 88, 9, 340, 570, 696, 728, 680, 570, 420, 256, 108, 10, 451, 770, 963, 1040, 1015, 906, 735, 528, 315, 130, 11, 584, 1012, 1290, 1428, 1440, 1344, 1162, 920, 648, 380, 154, 12

Offset: 1

Clark Kimberling, Feb 05 2011

A member of the accumulation chain ... < A185879 < A185877 < A185878 < A185880 < ...

See A144112 for the definition of accumulation array.

			Northwest corner:
  1,  4, 11,  24,  45, ...
  2, 10, 28,  60, 110, ...
  3, 18, 51, 108, 195, ...
  4, 28, 80, 168, 300, ...
  ...

G. C. Greubel, Table of n, a(n) for the first 50 rows, flattened

Cf. A144112, A185877, A185879.
Row 1 to 3: A006527, A006331, A064043.
Column 1 to 5: A000027, A028552, A140677, 12*A000096, 5*A130861.

f[n_, k_] := k*n*(2*k^2 - 3*k + 3*k*n - 3*n + 7)/6; Table[f[n - k + 1, k], {n,10}, {k, n, 1, -1}] // Flatten (* G. C. Greubel, Jul 21 2017 *)

T(n,k) = k*n*(2*k^2 -3*k +3*k*n -3*n +7)/6, k>=1, n>=1.

A227182 Simple self-inverse permutation of natural numbers: List each block of n^2 - n + 1 numbers from ((n-1)^3 + 2(n-1))/3 + 1 to (n^3 + 2n)/3 in reverse order.

Original entry on oeis.org

0, 1, 4, 3, 2, 11, 10, 9, 8, 7, 6, 5, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 45, 44, 43, 42, 41, 40, 39, 38, 37, 36, 35, 34, 33, 32, 31, 30, 29, 28, 27, 26, 25, 76, 75, 74, 73, 72, 71, 70, 69, 68, 67, 66, 65, 64, 63, 62, 61, 60, 59, 58, 57, 56, 55, 54, 53, 52, 51, 50, 49, 48, 47, 46

Offset: 0

Antti Karttunen, Jul 04 2013

nonn

In other words, after zero, list each block of A002061(n) numbers from A116731(n) to A006527(n) in reverse order.

Antti Karttunen, Table of n, a(n) for n = 0..9951
Index entries for sequences that are permutations of the natural numbers

Cf. A227177, A227179, A227147.

Flatten[(Reverse/@( (-1+#) (9-5 #+#^2)/3+Range[(#-2) (#-1)+1]-1)&)[Range[7]]] (* Peter J. C. Moses, Jul 11 2013 *)

(define (A227182 n) (- (A006527 (A227177 n)) (A227179 n)))

a(n) = A006527(A227177(n)) - A227179(n).

A129687 A129686 * A007318.

Original entry on oeis.org

1, 1, 1, 2, 2, 1, 2, 4, 3, 1, 2, 6, 7, 4, 1, 2, 8, 13, 11, 5, 1, 2, 10, 21, 24, 16, 6, 1, 2, 12, 31, 45, 40, 22, 7, 1, 2, 14, 43, 76, 85, 62, 29, 8, 1, 2, 16, 57, 119, 161, 147, 91, 37, 9, 1, 2, 18, 73, 176, 280, 308, 238, 128, 46, 10, 1, 2, 20, 91, 249, 456

Offset: 0

Gary W. Adamson, Apr 28 2007

Row sums = A084215: (1, 2, 5, 10, 20, 40, 80, ...). A007318 * A129686 = A124725.
From Philippe Deléham, Feb 12 2014: (Start)
Riordan array ((1+x^2)/(1-x), x/(1-x)).
Diagonal sums are A000032(n) - 0^n (cf. A000204).
T(n,0) = A046698(n+1).
T(n+1,1) = A004277(n).
T(n+2,2) = A002061(n+1).
T(n+3,3) = A006527(n+1) = A167875(n).
T(n+4,4) = A006007(n+1).
T(n+5,5) = A081282(n+1). (End)

			First few rows of the triangle:
  1;
  1,   1;
  2,   2,   1;
  2,   4,   3,   1;
  2,   6,   7,   4,   1;
  2,   8,  13,  11,   5,   1;
  2,  10,  21,  24,  16,   6,   1;
  2,  12,  31,  45,  40,  22,   7,   1;
  2,  14,  43,  76,  85,  62,  29,   8,   1;
  2,  16,  57, 119, 161, 147,  91,  37,   9,   1;
  ...

Cf. A129686, A007318, A124725.

Cf. Columns: A046698, A004277, A002061, A006527, A006007, A081282

A129686 * A007318 (Pascal's Triangle), as infinite lower triangular matrices.

T(n,k) = T(n-1,k) + T(n-1,k-1), T(0,0) = T(1,0) = T(1,1) = T(2,2) = 1, T(2,0) = T(2,1) = 2, T(n,k) = 0 if k<0 or if k>n. - Philippe Deléham, Feb 12 2014

More terms from Philippe Deléham, Feb 12 2014

A158822 Triangle read by rows, matrix triple product A000012 * A145677 * A000012.

Original entry on oeis.org

1, 3, 1, 6, 3, 2, 10, 6, 5, 3, 15, 10, 9, 7, 4, 21, 15, 14, 12, 9, 5, 28, 21, 20, 18, 15, 11, 6, 36, 28, 27, 25, 22, 18, 13, 7, 45, 36, 35, 33, 30, 26, 21, 15, 8, 55, 45, 44, 42, 39, 35, 30, 24, 17, 9, 66, 55, 54, 52, 49, 45, 40, 34, 27, 19, 10

Offset: 0

Gary W. Adamson and Roger L. Bagula, Mar 28 2009

			First few rows of the triangle =
   1;
   3,  1;
   6,  3,  2;
  10,  6,  5,  3;
  15, 10,  9,  7,  4;
  21, 15, 14, 12,  9,  5;
  28, 21, 10, 18, 15, 11,  6;
  36, 28, 27, 25, 22, 18, 13,  7;
  45, 36, 35, 33, 30, 26, 21, 15,  8;
  55, 45, 44, 42, 39, 35, 30, 24, 17,  9;
  66, 55, 54, 52, 49, 45, 40, 34, 27, 19, 10;
  78, 66, 65, 63, 60, 56, 51, 45, 38, 30, 21, 11;
  91, 78, 77, 75, 72, 68, 63, 57, 50, 42, 33, 23, 12;
  ...

G. C. Greubel, Rows n = 0..50 of the triangle, flattened

Cf. A000012, A000096, A000217, A006527, A034828, A055998, A145677, A134479.

T[n_, k_]:= If[k==0, Binomial[n+2, 2], (n+1-k)*(n+k)/2];
Table[T[n, k], {n,0,15}, {k,0,n}]//Flatten (* G. C. Greubel, Dec 26 2021 *)

def A158822(n,k):
    if (k==0): return binomial(n+2, 2)
    else: return (n-k+1)*(n+k)/2
flatten([[A158822(n,k) for k in (0..n)] for n in (0..15)]) # G. C. Greubel, Dec 26 2021

Triangle read by rows, A000012 * A145677 * A000012; where A000012 = an infinite lower triangular matrix: (1; 1,1; 1,1,1; ...), with all 1's.
From G. C. Greubel, Dec 26 2021: (Start)
T(n, k) = (n+1-k)*(n+k)/2 with T(n, 0) = binomial(n+2, 2).
Sum_{k=0..n} T(n, k) = (1/3)*(n+1)*(n^2 + 2*n + 3) = A006527(n+1).
Sum_{k=0..floor(n/2)} T(n-k, k) = binomial(n+2, 2) + A034828(n+1).
T(n, 1) = A000217(n).
T(n, 2) = A000096(n-1).
T(n, 3) = A055998(n-2).
T(2*n, n) = A134479(n). (End)

Definition corrected by Michael Somos, Nov 05 2011

A292022 a(n) = 4n(n^2 + 2).

Original entry on oeis.org

12, 48, 132, 288, 540, 912, 1428, 2112, 2988, 4080, 5412, 7008, 8892, 11088, 13620, 16512, 19788, 23472, 27588, 32160, 37212, 42768, 48852, 55488, 62700, 70512, 78948, 88032, 97788, 108240, 119412, 131328, 144012, 157488, 171780, 186912, 202908, 219792, 237588

Offset: 1

Eric W. Weisstein, Sep 07 2017

For n > 1, Wiener index of the 2n-crossed prism graph.

Eric Weisstein's World of Mathematics, Crossed Prism Graph.
Eric Weisstein's World of Mathematics, Wiener Index.
Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1).

Cf. A006527, A054602, A217873.

Table[4 n (n^2 + 2), {n, 50}]
LinearRecurrence[{4, -6, 4, -1}, {12, 48, 132, 288}, 20]
CoefficientList[Series[(12 (1 + x^2))/(-1 + x)^4, {x, 0, 20}], x]

a(n) = 4*n*(n^2 + 2).
a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4).
G.f.: 12*x*(1 + x^2)/(-1 + x)^4.
From Elmo R. Oliveira, Aug 09 2025: (Start)
E.g.f.: 4*x*(3 + 3*x + x^2)*exp(x).
a(n) = 12*A006527(n) = 4*A054602(n) = 3*A217873(n). (End)

A109876 Triangle read by rows: a(n, n) = n! and for 1 <= k < n, a(n, k) = Sum_{i=0..n-1} Product_{j=i+1..i+k} f(j, n), where for x <= y, f(x, y) = x and for x > y, f(x, y) = x-y.

Original entry on oeis.org

1, 3, 2, 6, 11, 6, 10, 24, 50, 24, 15, 45, 120, 274, 120, 21, 76, 252, 720, 1764, 720, 28, 119, 476, 1680, 5040, 13068, 5040, 36, 176, 828, 3520, 12960, 40320, 109584, 40320, 45, 249, 1350, 6750, 29880, 113400, 362880, 1026576, 362880, 55, 340, 2090, 12048

Offset: 1

Amarnath Murthy, Jul 10 2005

The first four columns (excluding the initial term of each) are A000217 (triangular numbers), A006527, A062026 and A062027. The first and third diagonals are both A000142 (factorials). The second diagonal is A000254.

Without the exception for k = n, a(n, n) would be n*n! (A001563(n)). For example, a(3, 3) would be 1*2*3 + 2*3*1 + 3*1*2 instead of 1*2*3. The author's original description did not mention the exception. I guess it didn't make sense to him to add n identical terms. - David Wasserman, Oct 01 2008

			a(5, 3) = 1*2*3 + 2*3*4 + 3*4*5 + 4*5*1 + 5*1*2 = 120.

Cf. A109877.

f(x, y) = if (x > y, x - y, x);
a(n, k) = if (n == k, n!, sum (i = 0, n - 1, prod (j = i + 1, i + k, f(j, n)))); \\ David Wasserman, Oct 01 2008

Edited and extended by David Wasserman, Oct 01 2008

A129312 A minimal 2 X 2 subdeterminant array.

Original entry on oeis.org

1, 2, 2, 3, 5, 3, 4, 8, 8, 4, 5, 11, 13, 11, 5, 6, 14, 18, 18, 14, 6, 7, 17, 23, 25, 23, 17, 7, 8, 20, 28, 32, 32, 28, 20, 8, 9, 23, 33, 39, 41, 39, 33, 23, 9, 10, 26, 38, 46, 50, 50, 46, 38, 26, 10, 11, 29, 43, 53, 59, 61, 59, 53, 43, 29, 11, 12, 32, 48, 60, 68, 72, 72, 68, 60

Offset: 1

Clark Kimberling, Apr 09 2007

Given that row 1 and column 1 are the sequence (1,2,3,4,...), T is the array of minimal positive subdeterminants in the sense that for each 2 X 2 submatrix
a b
c d,
d is the least integer for which the resulting
determinant is positive; indeed, the determinant is 1.
T(n,n)=A001844(n).
SUM{T(n,k): k=1,2,...,n}=A081436(n).
When T is written as the triangle
1
2 2
3 5 3
4 8 8 4
5 11 13 11 5, etc.,
the row sums are A006527 and the alternating row sums are 1,0,1,0,1,0,1,0,... (A059841).
The underlying function T is the same as in A244418, but this triangle's rows hold n+k constant, while in A244418, n is held constant on each row, and k <= n.
T(n,k) can be interpreted as a figurate number, with an (n-1) x (k-1) rectangle of dots interleaved with an n x k rectangle. The American flag illustrates T(5,6).

			Northwest corner:
1 2 3 4 5 6
2 5 8 11 14 17
3 8 13 18 23 28
4 11 18 25 32 39
T(2,2)=5 because 5 is the least positive integer x for which the determinant of the 2 X 2 matrix below is positive:
1 2
2 x

Cf. A001844, A081436, A006527, A059841.

Cf. A244418 (different triangle for the same function T).

(* Array version: *)
Grid[Table[SeriesCoefficient[Series[(n + (n - 1)*x)/(1 - x)^2, {x, 0, 12}], k], {n, 12}, {k, 0, 12}]] (* L. Edson Jeffery, Aug 23 2014 *)
(* Triangle version: *)
Grid[Table[SeriesCoefficient[Series[(n - k + (n - k - 1)*x)/(1 - x)^2, {x, 0, 12}], k], {n, 12}, {k, 0, n - 1}]] (* L. Edson Jeffery, Aug 23 2014 *)

T(n,k)=(2n-1)*k-n+1.

Connection to A244418 and interpretation as figurate numbers from Allan C. Wechsler, Nov 18 2018

A135184 Triangle read by rows: A000012 * A128229^2 as infinite lower triangular matrices.

Original entry on oeis.org

1, 3, 1, 5, 5, 1, 5, 11, 7, 1, 5, 11, 19, 9, 1, 5, 11, 19, 29, 11, 1, 5, 11, 19, 29, 41, 13, 1, 5, 11, 19, 29, 41, 55, 15, 1, 5, 11, 19, 29, 41, 55, 71, 17, 1, 5, 11, 19, 29, 41, 55, 71, 89, 19, 1, 5, 11, 19, 29, 41, 55, 71, 89, 109, 21, 1, 5, 11, 19, 29, 41, 55, 71, 89, 109, 131, 23, 1

Offset: 1

Gary W. Adamson, Nov 21 2007

Row sums = A006527: (1, 4, 11, 24, 45, 76, ...).

			First few rows of the triangle:
  1;
  3,  1;
  5,  5,  1;
  5, 11,  7,  1;
  5, 11, 19,  9,  1;
  5, 11, 19, 29, 11,  1;
  5, 11, 19, 29, 41, 13,  1;
  5, 11, 19, 29, 41, 55, 15,  1;
  ...

Cf. A006527, A128229.

a(19), a(20) corrected and more terms from Georg Fischer, Jun 05 2023

A292185 One-fifth of the rolling arithmetic mean of the fifth powers of the natural numbers taken five at a time.

Original entry on oeis.org

177, 488, 1159, 2460, 4781, 8656, 14787, 24068, 37609, 56760, 83135, 118636, 165477, 226208, 303739, 401364, 522785, 672136, 854007, 1073468, 1336093, 1647984, 2015795, 2446756, 2948697, 3530072, 4199983, 4968204, 5845205, 6842176, 7971051, 9244532, 10676113

Offset: 1

Robert G. Burns, Sep 12 2017

This method can be generalized. Replacing all the fives by any odd positive integer m, and taking m at a time, also gives an integer sequence.

If m is 3 then A006527 (from term 3) and A167875 (from term 2) are retrieved.

			a(1) = (1^5 + 2^5 + 3^5 + 4^5 +5^5)/25 = (1+32+243+1024+3125)/25 = 4425/25 = 177.
a(2) = (2^5 + 3^5 + 4^5 + 5^5 +6^5 )/25 = (32+243+1024+3125+7776)/25 = 12200/25 = 488.

Colin Barker, Table of n, a(n) for n = 1..1000
Index entries for linear recurrences with constant coefficients, signature (6,-15,20,-15,6,-1).

Cf. A006527, A167875.

(m(+/ % #) \ (1+i. 44)^(x: m))%m [m=.5 NB. See http://www.jsoftware.com

MovingAverage[Range[40]^5,5]/5 (* or *) LinearRecurrence[{6,-15,20,-15,6,-1},{177,488,1159,2460,4781,8656},40] (* Harvey P. Dale, Aug 03 2024 *)

Vec(x*(177 - 574*x + 886*x^2 - 714*x^3 + 301*x^4 - 52*x^5) / (1 - x)^6 + O(x^30)) \\ Colin Barker, Sep 18 2017

a(n) = ((n^5 + (n+1)^5 + (n+2)^5 + (n+3)^5 + (n+4)^5) /5) /5.
From Colin Barker, Sep 18 2017: (Start)
G.f.: x*(177 - 574*x + 886*x^2 - 714*x^3 + 301*x^4 - 52*x^5) / (1 - x)^6.
a(n) = 6*a(n-1)- 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6) for n>6.
(End)

A329523 a(n) = n * (binomial(n + 1, 3) + 1).

Original entry on oeis.org

0, 1, 4, 15, 44, 105, 216, 399, 680, 1089, 1660, 2431, 3444, 4745, 6384, 8415, 10896, 13889, 17460, 21679, 26620, 32361, 38984, 46575, 55224, 65025, 76076, 88479, 102340, 117769, 134880, 153791, 174624, 197505, 222564, 249935, 279756, 312169, 347320, 385359, 426440

Offset: 0

Ilya Gutkovskiy, Nov 15 2019

The n-th centered n-gonal pyramidal number.

			Square array begins:
  (0), 1,  2,   3,   4,    5,  ... A001477
   0, (1), 3,   7,  14,   25,  ... A004006
   0,  1, (4), 11,  24,   45,  ... A006527
   0,  1,  5, (15), 34,   65,  ... A006003 (partial sums of A005448)
   0,  1,  6,  19, (44),  85,  ... A005900 (partial sums of A001844)
   0,  1,  7,  23,  54, (105), ... A004068 (partial sums of A005891)
...
This sequence is the main diagonal of the array.

E. Deza and M. M. Deza, Figurate numbers, World Scientific Publishing (2012), 142.

Kelvin Voskuijl, Table of n, a(n) for n = 0..10000
Index entries for linear recurrences with constant coefficients, signature (5,-10,10,-5,1).

Cf. A000292, A000330, A002415, A002417, A006000, A006484, A008911, A050407, A060354, A100119, A188475 (first differences).

[ n*(Binomial(n+1,3)+1):n in [0..40]]; // Marius A. Burtea, Nov 15 2019

R:=PowerSeriesRing(Integers(), 41); [0] cat Coefficients(R!(x*(1-x+5*x^2-x^3)/(1-x)^5)); // Marius A. Burtea, Nov 15 2019

Table[n (Binomial[n + 1, 3] + 1), {n, 0, 40}]
nmax = 40; CoefficientList[Series[x (1 - x + 5 x^2 - x^3)/(1 - x)^5, {x, 0, nmax}], x]
LinearRecurrence[{5, -10, 10, -5, 1}, {0, 1, 4, 15, 44}, 41]

G.f.: x * (1 - x + 5*x^2 - x^3) / (1 - x)^5.
E.g.f.: exp(x) * x * (1 + x + x^2 + x^3 / 6).
a(n) = n * (n + 2) * (n^2 - 2*n + 3) / 6.
a(n) = n * (A000292(n-1) + 1).
a(n) = n + 2 * Sum_{k=1..n} A000330(k-1).
a(n) + a(-n) = 4 * A002415(n).

cp's OEIS Frontend

A185878 Accumulation array of A185877, by antidiagonals.

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A227182 Simple self-inverse permutation of natural numbers: List each block of n^2 - n + 1 numbers from ((n-1)^3 + 2*(n-1))/3 + 1 to (n^3 + 2*n)/3 in reverse order.

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A129687 A129686 * A007318.

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A158822 Triangle read by rows, matrix triple product A000012 * A145677 * A000012.

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A292022 a(n) = 4*n*(n^2 + 2).

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A109876 Triangle read by rows: a(n, n) = n! and for 1 <= k < n, a(n, k) = Sum_{i=0..n-1} Product_{j=i+1..i+k} f(j, n), where for x <= y, f(x, y) = x and for x > y, f(x, y) = x-y.

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A129312 A minimal 2 X 2 subdeterminant array.

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A135184 Triangle read by rows: A000012 * A128229^2 as infinite lower triangular matrices.

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A227182 Simple self-inverse permutation of natural numbers: List each block of n^2 - n + 1 numbers from ((n-1)^3 + 2(n-1))/3 + 1 to (n^3 + 2n)/3 in reverse order.

A292022 a(n) = 4n(n^2 + 2).