cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A006180 Witt vector *5!/5!.

Original entry on oeis.org

1, 472, 467133, 636430764, 1038934571875, 1903882757758426, 3782689379194538057, 7975541699963490241566, 17602442746255160006062232, 40278440105728693363331297293
Offset: 1

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Author

Keywords

Comments

If c is the Witt transform of b then b(n) = Sum_{d|n} A074650(n/d, c(d)).

References

  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Formula

Witt transform of A074654.

Extensions

More terms and formula from Christian G. Bower, Aug 28 2002

A363916 Array read by descending antidiagonals. A(n, k) = Sum_{d=0..k} A363914(k, d) * n^d.

Original entry on oeis.org

1, 0, 1, 0, 1, 1, 0, 0, 2, 1, 0, 0, 2, 3, 1, 0, 0, 6, 6, 4, 1, 0, 0, 12, 24, 12, 5, 1, 0, 0, 30, 72, 60, 20, 6, 1, 0, 0, 54, 240, 240, 120, 30, 7, 1, 0, 0, 126, 696, 1020, 600, 210, 42, 8, 1, 0, 0, 240, 2184, 4020, 3120, 1260, 336, 56, 9, 1
Offset: 0

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Author

Peter Luschny, Jul 04 2023

Keywords

Comments

Row n gives the number of n-ary sequences with primitive period k.
See A074650 and A143324 for combinatorial interpretations.

Examples

			Array A(n, k) starts:
[0] 1, 0,  0,   0,    0,     0,      0,       0,        0, ... A000007
[1] 1, 1,  0,   0,    0,     0,      0,       0,        0, ... A019590
[2] 1, 2,  2,   6,   12,    30,     54,     126,      240, ... A027375
[3] 1, 3,  6,  24,   72,   240,    696,    2184,     6480, ... A054718
[4] 1, 4, 12,  60,  240,  1020,   4020,   16380,    65280, ... A054719
[5] 1, 5, 20, 120,  600,  3120,  15480,   78120,   390000, ... A054720
[6] 1, 6, 30, 210, 1260,  7770,  46410,  279930,  1678320, ... A054721
[7] 1, 7, 42, 336, 2352, 16800, 117264,  823536,  5762400, ... A218124
[8] 1, 8, 56, 504, 4032, 32760, 261576, 2097144, 16773120, ... A218125
A000012|A002378| A047928   |   A218130     |      A218131
    A001477,A007531,    A061167,        A133499,   (diagonal A252764)
.
Triangle T(n, k) starts:
[0] 1;
[1] 0, 1;
[2] 0, 1,  1;
[3] 0, 0,  2,   1;
[4] 0, 0,  2,   3,   1;
[5] 0, 0,  6,   6,   4,   1;
[6] 0, 0, 12,  24,  12,   5,  1;
[7] 0, 0, 30,  72,  60,  20,  6, 1;
[8] 0, 0, 54, 240, 240, 120, 30, 7, 1;
		

Crossrefs

Variant: A143324.
Rows: A000007 (n=0), A019590 (n=1), A027375 (n=2), A054718 (n=3), A054719 (n=4), A054720, A054721, A218124, A218125.
Columns: A000012 (k=0), A001477 (k=1), A002378 (k=2), A007531(k=3), A047928, A061167, A218130, A133499, A218131.
Cf. A252764 (main diagonal), A074650, A363914.

Programs

  • Maple
    A363916 := (n, k) -> local d; add(A363914(k, d) * n^d, d = 0 ..k):
    for n from 0 to 9 do seq(A363916(n, k), k = 0..8) od;
  • SageMath
    def A363916(n, k): return sum(A363914(k, d) * n^d for d in range(k + 1))
    for n in range(9): print([A363916(n, k) for k in srange(9)])
    def T(n, k): return A363916(k, n - k)

Formula

If k > 0 then k divides A(n, k), see the transposed array of A074650.
If k > 0 then n divides A(n, k), see the transposed array of A143325.

A383023 Square array A(n,k), n >= 1, k >= 1, read by antidiagonals downwards, where A(n,k) is the n-th term of the inverse Weigh transform of j-> k^j.

Original entry on oeis.org

1, 2, 1, 3, 3, 0, 4, 6, 2, 1, 5, 10, 8, 6, 0, 6, 15, 20, 24, 6, 0, 7, 21, 40, 70, 48, 11, 0, 8, 28, 70, 165, 204, 124, 18, 1, 9, 36, 112, 336, 624, 690, 312, 36, 0, 10, 45, 168, 616, 1554, 2620, 2340, 834, 56, 0, 11, 55, 240, 1044, 3360, 7805, 11160, 8230, 2184, 105, 0
Offset: 1

Views

Author

Seiichi Manyama, Apr 12 2025

Keywords

Examples

			Square array begins:
  1,  2,   3,    4,     5,     6,      7, ...
  1,  3,   6,   10,    15,    21,     28, ...
  0,  2,   8,   20,    40,    70,    112, ...
  1,  6,  24,   70,   165,   336,    616, ...
  0,  6,  48,  204,   624,  1554,   3360, ...
  0, 11, 124,  690,  2620,  7805,  19656, ...
  0, 18, 312, 2340, 11160, 39990, 117648, ...
		

Crossrefs

Columns k=1..5 give A209229, A306156, A306157, A306158, A306159.
Cf. A074650.

Formula

A(n,k) = (1/n) * (k^n + Sum_{d
Product_{n>=1} (1 + x^n)^A(n,k) = 1/(1 - k*x).

A347277 Table T(n,k) read by downward antidiagonals: A quotient belonging to a generalization of Euler's theorem.

Original entry on oeis.org

0, 1, 0, 2, 1, 0, 3, 3, 2, 0, 4, 6, 8, 3, 0, 5, 10, 20, 18, 6, 0, 6, 15, 40, 60, 48, 8, 0, 7, 21, 70, 150, 204, 108, 18, 0, 8, 28, 112, 315, 624, 640, 312, 30, 0, 9, 36, 168, 588, 1554, 2500, 2340, 810, 56, 0, 10, 45, 240, 1008, 3360, 7560, 11160, 8160, 2184, 96, 0
Offset: 1

Author

Franz Vrabec, Aug 26 2021

Keywords

Comments

The quotient T(n,k) = (k^n - k^(n-phi(n)))/n results from the generalization k^n == k^(n-phi(n)) (mod n) of Euler's theorem (see Sierpiński, p. 243).
The n-th row of the table is equal to the n-th row of A074650 iff n = p^j (p prime, j>=1).

Examples

			T(4,3) = (3^4 - 3^2)/4 = 18.
Square array starts:
  0, 1,   2,   3,    4,    5, ...
  0, 1,   3,   6,   10,   15, ...
  0, 2,   8,  20,   40,   70, ...
  0, 3,  18,  60,  150,  315, ...
  0, 6,  48, 204,  624, 1554, ...
  0, 8, 108, 640, 2500, 7560, ...
		

References

  • W. Sierpiński, Elementary Theory of Numbers, Warszawa, 1964.

Crossrefs

Cf. A074650.

Programs

  • Maple
    with(numtheory):
    T:= proc(n, k) (k^n-k^(n-phi(n)))/n end:
    seq(seq(T(i, 1+d-i), i=1..d), d=1..11);
  • PARI
    T(n,k) = (k^n - k^(n - eulerphi(n)))/n; \\ Jinyuan Wang, Aug 28 2021

Formula

T(n,k) = (k^n - k^(n - phi(n)))/n.

Extensions

More terms from Jinyuan Wang, Aug 28 2021

A383042 Square array A(n,k), n >= 1, k >= 1, read by antidiagonals downwards, where A(n,k) is the n-th term of the inverse Euler transform of j-> k^(j-1).

Original entry on oeis.org

1, 1, 0, 1, 1, 0, 1, 2, 2, 0, 1, 3, 6, 3, 0, 1, 4, 12, 15, 6, 0, 1, 5, 20, 42, 42, 9, 0, 1, 6, 30, 90, 156, 107, 18, 0, 1, 7, 42, 165, 420, 554, 294, 30, 0, 1, 8, 56, 273, 930, 1910, 2028, 780, 56, 0, 1, 9, 72, 420, 1806, 5155, 8820, 7350, 2128, 99, 0
Offset: 1

Author

Seiichi Manyama, Apr 13 2025

Keywords

Examples

			Square array begins:
  1,  1,   1,    1,    1,     1,     1, ...
  0,  1,   2,    3,    4,     5,     6, ...
  0,  2,   6,   12,   20,    30,    42, ...
  0,  3,  15,   42,   90,   165,   273, ...
  0,  6,  42,  156,  420,   930,  1806, ...
  0,  9, 107,  554, 1910,  5155, 11809, ...
  0, 18, 294, 2028, 8820, 28830, 77658, ...
  ...
		

Crossrefs

Columns k=1..5 give A000007, A059966, A065178, A065179, A065180.
Main diagonal gives A306173.
Cf. A065177 (another version).

Programs

  • PARI
    a(n, k) = sumdiv(n, d, moebius(n/d)*(k^d-(k-1)^d))/n;

Formula

A(n,k) = (1/n) * Sum_{d|n} mu(n/d) * (k^d - (k-1)^d).
A(n,k) = (1/n) * (k^n - (k-1)^n - Sum_{d
A(n,k) = A074650(n,k) - A074650(n,k-1).
Product_{n>=1} 1/(1 - x^n)^A(n,k) = (1 - (k-1)*x)/(1 - k*x).
G.f. of column k: Sum_{j>=1} mu(j) * log(1 + x^j/(1 - k*x^j)) / j.
Previous Showing 51-55 of 55 results.