María Merino has authored 41 sequences. Here are the ten most recent ones:
A307429
Triangle read by rows: T(n,k) is the number of permutations of {1..n} at Kendall tau distance k of permutation sigma1 and k+1 Kendall tau distance of permutation sigma2, where sigma1 and sigma2 are at Kendall tau distance 1.
Original entry on oeis.org
1, 1, 0, 1, 1, 1, 0, 1, 2, 3, 3, 2, 1, 0, 1, 3, 6, 9, 11, 11, 9, 6, 3, 1, 0, 1, 4, 10, 19, 30, 41, 49, 52, 49, 41, 30, 19, 10, 4, 1, 0, 1, 5, 15, 34, 64, 105, 154, 205, 250, 281, 292, 281, 250, 205, 154, 105, 64, 34, 15, 5, 1, 0
Offset: 1
Triangle begins:
1;
1, 0;
1, 1, 1, 0;
1, 2, 3, 3, 2, 1, 0;
1, 3, 6, 9, 11, 11, 9, 6, 3, 1, 0;
1, 4, 10, 19, 30, 41, 49, 52, 49, 41, 30, 19, 10, 4, 1, 0;
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T[n_] := Module[{polcoef, svalues = {}, si, j, k, c}, polcoef = CoefficientList[Series[QFactorial[n, c], {c, 0, n (n - 1)/2}], c]; For[j = 1, j <= Length[polcoef], j++, si = 0; For[k = 1, k <= j, k++, si = si + polcoef[[k]]*(-1)^(j - k)]; AppendTo[svalues, si]]; Return[svalues]]; Catenate[Table[T[n], {n, 1, 7}]]
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S(n, k) = my(A=1+x); for(i=1, n, A = 1 + intformal(A - q*subst(A, x, q*x +x^2*O(x^n)))/(1-q)); polcoeff(n!*polcoeff(A, n, x), k, q); \\ A008302
T(n, k) = sum(i=0, k, (-1)^(k-i)*S(n,i));
tabf(nn) = for (n=1, nn, for (k=0, n*(n-1)/2, print1(T(n, k), ", ")); print); \\ Michel Marcus, Apr 10 2019
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from sage.combinat.q_analogues import q_factorial
def A307429_row(n):
qf = q_factorial(n).list()
return [sum((-1)^(k-j)*qf[j] for j in range(k+1)) for k in range(n*(n-1)//2 + 1)]
for n in range(1, 7): print(A307429_row(n)) # Peter Luschny, Sep 01 2022
A287384
Triangle read by rows: T(n,m) is the number of inequivalent n X m matrices under action of the Klein group, with one-tenth each of 1's, 2's, 3's, 4's, 5's, 6's, 7's, 8's, 9's and 0's (ordered occurrences rounded up/down if n*m != 0 mod 10).
Original entry on oeis.org
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 29937600, 81729648000, 1, 1, 907200, 10216209600, 593970221376000, 15584018578345728000, 1, 1, 29937600, 6252318979200, 1870082229375360000, 1096699334071461120000000, 375493744214599112902800000000
Offset: 0
For n = 4 and m = 3 the T(4,3)=29937600 solutions are colorings of 4 X 3 matrices in 10 colors inequivalent under the action of the Klein group with exactly 2, 2, 1, 1, 1, 1, 1, 1, 1, 1 occurrences of each color (coefficient of x1^2 x2^2 x3^1 x4^1 x5^1 x6^1 x7^1 x8^1 x9^1 x10^1).
Triangle begins:
==========================================
n\m | 0 1 2 3 4
----|-------------------------------------
0 | 1
1 | 1 1
2 | 1 1 1
3 | 1 1 1 1
4 | 1 1 1 29937600 81729648000
A287383
Triangle read by rows: T(n,m) is the number of inequivalent n X m matrices under action of the Klein group, with one-ninth each of 1's, 2's, 3's, 4's, 5's, 6's, 7's, 8's and 9's (ordered occurrences rounded up/down if n*m != 0 mod 9).
Original entry on oeis.org
1, 1, 1, 1, 1, 1, 1, 1, 1, 90720, 1, 1, 1, 14968800, 40864824000, 1, 1, 453600, 5108114880, 131993382447360, 3463115239584000000
Offset: 0
For n = 3 and m = 3 the T(3,3) = 90720 solutions are colorings of 3 X 3 matrices in 9 colors inequivalent under the action of the Klein group with exactly 1 occurrence of each color (coefficient of x1^1, x2^1, x3^1, x4^1, x5^1, x6^1, x7^1, x8^1, x9^1).
Triangle begins:
===================================================================
n\m | 0 1 2 3 4 5
----|--------------------------------------------------------------
0 | 1
1 | 1 1
2 | 1 1 1
3 | 1 1 1 90720
4 | 1 1 1 14968800 40864824000
5 | 1 1 453600 5108114880 131993382447360 3463115239584000000
A287378
Triangle read by rows: T(n,m) is the number of inequivalent n X m matrices under action of the Klein group, with one-eighth each of 1's, 2's, 3's, 4's, 5's, 6's, 7's and 8's (ordered occurrences rounded up/down if n*m != 0 mod 8).
Original entry on oeis.org
1, 1, 1, 1, 1, 1, 1, 1, 1, 45360, 1, 1, 10080, 7484544, 20432442240, 1, 1, 226800, 2554075440, 29331862801920, 577185873264000000
Offset: 0
For n = 4 and m = 2, the T(4,2) = 10080 solutions are colorings of 4 X 2 matrices in 8 colors inequivalent under the action of the Klein group with exactly 1 occurrence of each color (coefficient of x1^1, x2^1, x3^1, x4^1, x5^1, x6^1, x7^1, x8^1).
Triangle begins:
=================================================================
n\m | 0 1 2 3 4 5
----|------------------------------------------------------------
0 | 1
1 | 1 1
2 | 1 1 1
3 | 1 1 1 45360
4 | 1 1 10080 7484544 20432442240
5 | 1 1 226800 2554075440 29331862801920 577185873264000000
A287377
Triangle read by rows: T(n,m) is the number of inequivalent n X m matrices under action of the Klein group, with one-seventh each of 1's, 2's, 3's, 4's, 5's, 6's and 7's (ordered occurrences rounded up/down if n*m != 0 mod 7).
Original entry on oeis.org
1, 1, 1, 1, 1, 1, 1, 1, 1, 22680, 1, 1, 5040, 3742560, 4540536000, 1, 1, 113400, 851370480, 6518191680000, 54111175679736000
Offset: 0
For n = 4 and m = 2 the T(4,2) = 5040 solutions are colorings of 4 X 2 matrices in 7 colors inequivalent under the action of the Klein group with exactly 2, 1, 1, 1, 1, 1, 1 occurrences of each color (coefficient of x1^2 x2^1 x3^1 x4^1 x5^1 x6^1 x7^1).
Triangle begins:
==============================================================
n\m | 0 1 2 3 4 5
----|---------------------------------------------------------
0 | 1
1 | 1 1
2 | 1 1 1
3 | 1 1 1 22680
4 | 1 1 5040 3742560 4540536000
5 | 1 1 113400 851370480 6518191680000 54111175679736000
A287261
Number of inequivalent n X n matrices over an alphabet of size 10 under action of dihedral group of the square D_4, with one-tenth of 1's, 2's, 3's, 4's, 5's, 6's, 7's, 8's, 9's and 0's (ordered occurrences rounded up/down if n^2 != 0 mod 10).
Original entry on oeis.org
1, 1, 1, 1, 40864828320, 7792009289281728000, 187746872107299580970294400000, 614005731326101652800803825889630961295360, 176445174659483893854948844253232539237396497554309120000, 7090469783239448892319287907564531885316857076509137838529329991091840000
Offset: 0
For n = 3 the a(4) = 40864828320 solutions are colorings of 4 X 4 matrices in 10 colors inequivalent under the action of D_4 with exactly occurrences 2, 2, 2, 2, 2, 2, 1, 1, 1, 1 of each color (coefficient of x1^2 x2^2 x3^2 x4^2 x5^2 x6^2 x7^1 x8^1 x9^1 x10^1).
A287250
Number of inequivalent n X n matrices over GF(9) under action of dihedral group of the square D_4, with one-ninth each of 1's, 2's, 3's, 4's, 5's, 6's, 7's, 8's and 9's (ordered occurrences rounded up/down if n^2 != 0 mod 9).
Original entry on oeis.org
1, 1, 1, 45360, 20432427120, 1731557619792000000, 17601269260059379482191694720, 11370476506038919496334983007474778275840, 944848320304251231447932170156537415535539635814400000, 6641336088298446224006555306105706090482482272285249518936232000000000
Offset: 0
For n = 3 the a(3) = 45360 solutions are colorings of 3 X 3 matrices in 9 colors inequivalent under the action of D_4 with exactly 1 occurrence of each color (coefficient of x1^1 x2^1 x3^1 x4^1 x5^1 x6^1 x7^1 x8^1 x9^1).
A287249
Number of inequivalent n X n matrices over GF(8) under action of dihedral group of the square D_4, with one-eighth each of 1's, 2's, 3's, 4's, 5's, 6's, 7's and 8's (ordered occurrences rounded up/down if n^2 != 0 mod 8).
Original entry on oeis.org
1, 1, 1, 22680, 10216251360, 288592936632000000, 675888739586283307003920000, 150403128386758194407881602780164966400, 2270715491453850844620503532869818724155487772912000, 2190916399747036514334089808617857198357442887303702763561256837120
Offset: 0
For n = 3 the a(4) = 10216251360 solutions are colorings of 4 X 4 matrices in 8 colors inequivalent under the action of D_4 with exactly 2 occurrences of each color (coefficient of x1^2 x2^2 x3^2 x4^2 x5^2 x6^2 x7^2 x8^2).
A287245
Number of inequivalent n X n matrices over GF(7) under action of dihedral group of the square D_4, with one-seventh each of 1's, 2's, 3's, 4's, 5's, 6's and 7's (ordered occurrences rounded up/down if n^2 != 0 mod 7).
Original entry on oeis.org
1, 1, 1, 11340, 2270280240, 27055587870486000, 21628439666761521875561280, 920451958269648700957746787694592000, 1914192808178753950843058828570207003149548000000, 216425158352284448578663515683744576588775769063470820304640000
Offset: 0
For n = 3 the a(3) = 11340 solutions are colorings of 3 X 3 matrices in 7 colors inequivalent under the action of D_4 with exactly occurrences 2, 2, 1, 1, 1, 1, 1 of each color (coefficient of x1^2 x2^2 x3^1 x4^1 x5^1 x6^1 x7^1).
A287239
Number of inequivalent n X n matrices over an alphabet of size 6 under action of dihedral group of the square D_4, with one-sixth each of 1s, 2s, 3s, 4s, 5s and 6s (ordered occurrences rounded up/down if n^2 != 0 mod 6).
Original entry on oeis.org
1, 1, 1, 5688, 504508320, 2029169127793680, 333772217080092664473600, 1966297518276227170017585421188600, 474436367892839446541884570454351985506872320, 4529567636413022031420100639004131328550592354551163392000, 1664947024157601976065851576560401128416782438266187161307818265349050000
Offset: 0
For n = 3 the a(3) = 5688 solutions are colorings of 3 X 3 matrices in 6 colors inequivalent under the action of D_4 with exactly 2 occurrences of each color (coefficient of x1^2 x2^2 x3^2 x4^2 x5^2 x6^2).
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