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.

User: James Rayman

James Rayman's wiki page.

James Rayman has authored 9 sequences.

A353196 Number of stabilizer states on n qubits.

Original entry on oeis.org

6, 60, 1080, 36720, 2423520, 315057600, 81284860800, 41780418451200, 42866709330931200, 87876754128408960000, 360118938418219918080000, 2950814581398894008747520000, 48352047730802277227336862720000, 1584496604138390624739828991334400000
Offset: 1

Author

James Rayman, Apr 29 2022

Keywords

Comments

A stabilizer state is a quantum state on n qubits prepared by applying a series of Hadamard, CNOT, and S gates to the all-zero state. There are only a finite number of such states for any n.

Examples

			For n = 1, the a(1) = 6 states are |0>, |1>, |+>, |->, |i>, and |-i>.
		

Crossrefs

Programs

  • Mathematica
    Table[2^n * QPochhammer[-2, 2, n], {n, 13}] (* Amiram Eldar, Aug 17 2025 *)
  • Python
    def a(n):
        ans = 2 ** n
        for i in range(1, n+1):
            ans *= 2 ** i + 1
        return ans
    
  • Python
    from math import prod
    def A353196(n): return prod((1<Chai Wah Wu, Jun 20 2022

Formula

a(n) = 2^n*Product_{i=1..n} (2^i+1).
a(n) = A000079(n)*A028362(n+1).
a(n) ~ c * 2^(n*(n+3)/2) where c = Product_{k>=1} (1 + 1/2^k) = A079555. - Amiram Eldar, Aug 17 2025

A342627 Second differences of the y-coordinates of the vertices of the Babylonian Wurm.

Original entry on oeis.org

0, -1, -1, -1, -1, 0, 0, -1, 0, 1, 1, -1, 2, -1, -2, -1, -1, 0, 0, 1, -1, -1, 0, 1, -1, 0, 1, -2, 0, 0, 2, 3, -2, 1, 4, 1, 1, 3, -2, 1, 3, 1, 2, 0, -1, 1, -2, 2, -1, 2, 0, 0, -3, -1, -1, -2, -4, -1, -4, 3, -5, 4, -3, 2, -5, -1, -2, 1, -2, 0, 1, 2, -1, -1, -1
Offset: 1

Author

James Rayman, Apr 18 2021

Keywords

Comments

Equivalently, the first differences of A342625.

Crossrefs

See A256175 for the definition of the Babylonian Wurm.
See A342622 and A342623 for the coordinates of the Wurm.
See A342624 and A342625 for the first differences.
See A342626 for the second differences of the x-coordinates.

Programs

  • Python
    for i in range(10000): print(i+1, wurm(i+2)[1] - 2*wurm(i+1)[1] + wurm(i)[1]) # wurm is defined in the program for A256175

Formula

a(n) = A342623(n+2) - 2*A342623(n+1) + A342623(n).

A342626 Second differences of the x-coordinates of the vertices of the Babylonian Wurm.

Original entry on oeis.org

1, 1, 0, 0, -2, -1, -1, 2, 1, 2, 1, 0, 1, 0, -1, -1, -3, -1, -1, -2, 1, 3, 1, 3, -2, 1, 2, -5, -1, -1, -4, -2, 1, -1, -1, 0, 0, 1, -1, 0, 2, 1, 5, -1, -3, 2, -4, 3, -2, 6, 1, 1, 6, 1, 1, 1, 1, 0, -1, 1, -2, 2, -1, 1, -3, -1, -3, 2, -5, 1, 3, 3, -1, -1, -2, -5
Offset: 1

Author

James Rayman, Apr 17 2021

Keywords

Comments

Equivalently, the first differences of A342624.

Crossrefs

See A256175 for the definition of the Babylonian Wurm.
See A342622 and A342623 for the coordinates of the Wurm.
See A342624 and A342625 for the first differences.
See A342627 for the second differences of the y-coordinates.

Programs

  • Python
    for i in range(10000): print(i+1, wurm(i+2)[0] - 2*wurm(i+1)[0] + wurm(i)[0]) # wurm is defined in the program for A256175

Formula

a(n) = A342622(n+2) - 2*A342622(n+1) + A342622(n).

A343484 Number of equivalence classes of length n squarefree reduced words over {0, 1, 2, 3} under action of renaming symbols.

Original entry on oeis.org

0, 1, 1, 2, 3, 5, 8, 13, 18, 27, 41, 62, 90, 134, 198, 293, 423, 619, 908, 1329, 1938, 2832, 4142, 6061, 8824, 12879, 18794, 27425, 39977, 58333, 85109, 124180, 180994, 263931, 384933, 561402, 818617, 1193841, 1740980, 2538896, 3702022, 5398458, 7872351
Offset: 0

Author

James Rayman, Apr 16 2021

Keywords

Comments

Any equivalence class of words with length at least 2 has exactly 8 members.

Examples

			a(5) = 5 corresponds to the 5 words 01210, 01030, 01230, 01032, and 01232.
		

Crossrefs

Formula

a(n) = A343421(n)/8 for n >= 2.

A342625 The y-coordinates of the vectors used to construct the Babylonian Wurm.

Original entry on oeis.org

1, 1, 0, -1, -2, -3, -3, -3, -4, -4, -3, -2, -3, -1, -2, -4, -5, -6, -6, -6, -5, -6, -7, -7, -6, -7, -7, -6, -8, -8, -8, -6, -3, -5, -4, 0, 1, 2, 5, 3, 4, 7, 8, 10, 10, 9, 10, 8, 10, 9, 11, 11, 11, 8, 7, 6, 4, 0, -1, -5, -2, -7, -3, -6, -4, -9
Offset: 1

Author

James Rayman, Apr 09 2021

Keywords

Comments

Equivalently, this sequence gives the differences of the y-coordinates of successive vertices of the Babylonian Wurm.

Crossrefs

See A256175 for the definition of the Babylonian Wurm.
See A342624 for the x-coordinates.

Programs

  • Python
    for i in range(10000): print(i+1, wurm(i+1)[1] - wurm(i)[1]) # wurm is defined in the program for A256175.

Formula

a(n) = A342623(n+1) - A342623(n).

A342624 The x-coordinates of the vectors used to construct the Babylonian Wurm.

Original entry on oeis.org

0, 1, 2, 2, 2, 0, -1, -2, 0, 1, 3, 4, 4, 5, 5, 4, 3, 0, -1, -2, -4, -3, 0, 1, 4, 2, 3, 5, 0, -1, -2, -6, -8, -7, -8, -9, -9, -9, -8, -9, -9, -7, -6, -1, -2, -5, -3, -7, -4, -6, 0, 1, 2, 8, 9, 10, 11, 12, 12, 11, 12, 10, 12, 11, 12, 9, 8, 5, 7, 2
Offset: 1

Author

James Rayman, Apr 09 2021

Keywords

Comments

Equivalently, this sequence gives the differences of the x-coordinates of successive vertices of the Babylonian Wurm.

Crossrefs

See A256175 for the definition of the Babylonian Wurm.
See A342625 for the y-coordinates.

Programs

  • Python
    for i in range(10000): print(i+1, wurm(i+1)[0] - wurm(i)[0]) # wurm is defined in the program for A256175.

Formula

a(n) = A342622(n+1) - A342622(n).

A342622 The x-coordinates of the vertices of the Babylonian Wurm.

Original entry on oeis.org

0, 0, 1, 3, 5, 7, 7, 6, 4, 4, 5, 8, 12, 16, 21, 26, 30, 33, 33, 32, 30, 26, 23, 23, 24, 28, 30, 33, 38, 38, 37, 35, 29, 21, 14, 6, -3, -12, -21, -29, -38, -47, -54, -60, -61, -63, -68, -71, -78, -82, -88, -88, -87, -85, -77, -68, -58, -47, -35
Offset: 1

Author

James Rayman, Mar 16 2021

Keywords

Crossrefs

See A256175 for the definition of the Babylonian Wurm.
See A342623 for the y-coordinates.

Programs

  • Python
    for i in range(10000): print(i+1, wurm(i)[0]) # wurm is defined in the program for A256175.

A342623 The y-coordinates of the vertices of the Babylonian Wurm.

Original entry on oeis.org

0, 1, 2, 2, 1, -1, -4, -7, -10, -14, -18, -21, -23, -26, -27, -29, -33, -38, -44, -50, -56, -61, -67, -74, -81, -87, -94, -101, -107, -115, -123, -131, -137, -140, -145, -149, -149, -148, -146, -141, -138, -134, -127, -119, -109, -99, -90, -80
Offset: 1

Author

James Rayman, Mar 17 2021

Keywords

Crossrefs

See A256175 for the definition of the Babylonian Wurm.
See A342622 for the x-coordinates.

Programs

  • Python
    for i in range(10000): print(i+1, wurm(i)[1]) # wurm is defined in the program for A256175.

A340727 a(n) is the smallest integer that can be written as a product of n distinct integers > 1 in at least two different ways.

Original entry on oeis.org

12, 48, 240, 1440, 8640, 60480, 604800, 5443200, 59875200, 718502400, 9340531200, 124540416000, 1743565824000, 29640619008000, 502146957312000, 8536498274304000, 162193467211776000, 3406062811447296000, 68121256228945920000, 1498667637036810240000
Offset: 2

Author

James Rayman, Jan 17 2021

Keywords

Examples

			a(2) = 12 since 12 = 2*6 = 3*4.
a(4) = 240 since 240 = 2*3*4*10 = 2*3*5*8.
		

Crossrefs

Cf. A081957.

Programs

  • Python
    from heapq import *
    import math
    def a(n):
        prev, visited, v = 0, set(), list(range(2, n+2))
        pq = [(math.factorial(n+1), v)]
        while True:
            prod, v = heappop(pq)
            if tuple(v) in visited: continue
            visited.add(tuple(v))
            if prev != prod: prev = prod
            else: return prod
            for i in range(n):
                if i == n-1 or v[i] + 1 < v[i+1]:
                    u = v[:]
                    u[i] += 1
                    heappush(pq, (prod // v[i] * u[i], u))