A125274
Eigensequence of triangle A078812: a(n) = Sum_{k=0..n-1} A078812(n-1,k)*a(k) for n > 0 with a(0)=1.
Original entry on oeis.org
1, 1, 3, 10, 42, 210, 1199, 7670, 54224, 418744, 3499781, 31425207, 301324035, 3069644790, 33078375153, 375634524357, 4480492554993, 55971845014528, 730438139266281, 9935106417137098, 140553930403702487
Offset: 0
a(3) = 3*(1) + 4*(1) + 1*(3) = 10;
a(4) = 4*(1) + 10*(1) + 6*(3) + 1*(10) = 42;
a(5) = 5*(1) + 20*(1) + 21*(3) + 8*(10) + 1*(42) = 210.
Triangle A078812(n,k) = binomial(n+k+1, n-k) begins:
1;
2, 1;
3, 4, 1;
4, 10, 6, 1;
5, 20, 21, 8, 1;
6, 35, 56, 36, 10, 1; ...
where g.f. of column k = 1/(1-x)^(2*k+2).
-
a[0] = 1; a[n_] := a[n] = Sum[Binomial[n+k, n-k-1] * a[k], {k, 0, n-1}]; Array[a, 20, 0] (* Amiram Eldar, Nov 24 2018 *)
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a(n)=if(n==0,1,sum(k=0,n-1, a(k)*binomial(n+k, n-k-1)))
A351813
G.f. A(x) satisfies: A(x) = 1 + x * A(x/(1 - x)^3) / (1 - x).
Original entry on oeis.org
1, 1, 2, 7, 32, 179, 1184, 8977, 76391, 719132, 7405261, 82654011, 992533974, 12744345310, 174073918884, 2518084939316, 38429337167618, 616676966998463, 10374679318111371, 182506045254212184, 3349265281648290030, 63984975864984809787, 1270096455615572678617
Offset: 0
-
nmax = 22; A[] = 0; Do[A[x] = 1 + x A[x/(1 - x)^3]/(1 - x) + O[x]^(nmax + 1) // Normal, nmax + 1]; CoefficientList[A[x], x]
a[0] = 1; a[n_] := a[n] = Sum[Binomial[n + 2 k - 1, n - k - 1] a[k], {k, 0, n - 1}]; Table[a[n], {n, 0, 22}]
A351814
G.f. A(x) satisfies A(x) = 1 + x * A(x/(1 - x)^4) / (1 - x).
Original entry on oeis.org
1, 1, 2, 8, 42, 272, 2115, 19010, 192760, 2172468, 26896081, 362184998, 5262526484, 81969555736, 1361249430071, 23989460080079, 446832403813788, 8765575657218860, 180544405959236487, 3893718987163468969, 87711985393624557487, 2059264143275898894916
Offset: 0
-
nmax = 21; A[] = 0; Do[A[x] = 1 + x A[x/(1 - x)^4]/(1 - x) + O[x]^(nmax + 1) // Normal, nmax + 1]; CoefficientList[A[x], x]
a[0] = 1; a[n_] := a[n] = Sum[Binomial[n + 3 k - 1, n - k - 1] a[k], {k, 0, n - 1}]; Table[a[n], {n, 0, 21}]
A351815
G.f. A(x) satisfies A(x) = 1 + x * A(x/(1 - x)^5) / (1 - x).
Original entry on oeis.org
1, 1, 2, 9, 53, 386, 3422, 35300, 412084, 5364255, 76952267, 1203835714, 20362911276, 369906504888, 7175947738672, 147944905766929, 3227970924123268, 74264452788294013, 1795825803391367571, 45514495928632484735, 1205981001167335524448, 33331235326744168532151
Offset: 0
-
nmax = 21; A[] = 0; Do[A[x] = 1 + x A[x/(1 - x)^5]/(1 - x) + O[x]^(nmax + 1) // Normal, nmax + 1]; CoefficientList[A[x], x]
a[0] = 1; a[n_] := a[n] = Sum[Binomial[n + 4 k - 1, n - k - 1] a[k], {k, 0, n - 1}]; Table[a[n], {n, 0, 21}]
Original entry on oeis.org
1, 1, 2, 6, 24, 122, 758, 5606, 48378, 479532, 5390940, 68022932, 954948752, 14804391270, 251815549396, 4673137101108, 94148342547146, 2050127343000170, 48061939075355080, 1208742383083994580, 32507565146820336836, 932149980847656487522, 28423646163259392354386, 919399182232129554488328
Offset: 0
Triangle A054142 begins:
1;
1, 1;
1, 3, 1;
1, 5, 6, 1;
1, 7, 15, 10, 1;
1, 9, 28, 35, 15, 1;
...
a(3) = 6 = 1*1 + 3*1 + 1*2
a(4) = 24 = 1*1 + 5*1 + 6*2 + 1*6
-
A054142(n, k) = binomial(2*n-k, k);
a(n) = if (n==0, 1, sum(k=0, n-1, A054142(n-1,k)*a(k))); \\ too slow
lista(nn) = my(v=vector(nn)); v[1] = 1; for (n=2, nn, v[n] = sum(k=0, n-1, A054142(n-2,k)*v[k+1]);); v; \\ Michel Marcus, Jan 17 2025
A144252
Eigentriangle, row sums = A144251 shifted, right border = A144251.
Original entry on oeis.org
1, 1, 1, 1, 3, 2, 1, 5, 12, 6, 1, 7, 30, 60, 24, 1, 9, 56, 210, 360, 122, 1, 11, 90, 504, 1680, 2562, 758, 1, 13, 132, 990, 5040, 15372, 21224, 5606, 1, 15, 182, 1716, 11880, 36364, 159180, 201816, 47378, 1, 17, 240, 2730, 24024, 157014, 700392, 1849980, 2177010, 479532
Offset: 0
First few rows of the triangle =
1;
1, 1;
1, 3, 2;
1, 5, 12, 6;
1, 7, 30, 60, 24;
1, 9, 56, 210, 360, 122;
1, 11, 90, 504, 1680, 2562, 758;
1, 13, 132, 990, 5040, 15372, 21224, 5606;
...
The triangle is generated from A054142 and its own eigensequence, A144251.
Triangle A054142 =
1;
1, 1;
1, 3, 1;
1, 5, 6, 1;
1, 7, 15, 10, 1;
...
The eigensequence of A054142 = A144251: (1, 1, 2, 6, 24, 122, 758, 5606,...);
Example: row 3 of A144252 = (1, 5, 12, 6) = termwise products of (1, 5, 6, 1) and (1, 1, 2, 6) = (1*1, 5*1, 6*2, 1*6).
-
A054142(n, k) = binomial(2*n-k, k);
V144251(nn) = my(v=vector(nn)); v[1] = 1; for (n=2, nn, v[n] = sum(k=0, n-1, A054142(n-2,k)*v[k+1]);); v;
row(n) = my(v=V144251(n+1)); vector(n+1, k, A054142(n,k-1) * v[k]); \\ Michel Marcus, Jan 18 2025
A132427
Triangle, read by rows of 2n+1 terms, where T(n,k) = T(n,k-1) + T(n-1,k-2) for n>0, 10 and T(0,0)=1.
Original entry on oeis.org
1, 1, 1, 2, 2, 2, 3, 4, 6, 6, 6, 8, 10, 13, 17, 23, 23, 23, 29, 35, 43, 53, 66, 83, 106, 106, 106, 129, 152, 181, 216, 259, 312, 378, 461, 567, 567, 567, 673, 779, 908, 1060, 1241, 1457, 1716, 2028, 2406, 2867, 3434, 3434, 3434, 4001, 4568, 5241, 6020, 6928, 7988
Offset: 0
Triangle begins:
1;
1, 1, 2;
2, 2, 3, 4, 6;
6, 6, 8, 10, 13, 17, 23;
23, 23, 29, 35, 43, 53, 66, 83, 106;
106, 106, 129, 152, 181, 216, 259, 312, 378, 461, 567;
567, 567, 673, 779, 908, 1060, 1241, 1457, 1716, 2028, 2406, 2867, 3434; ...
-
t[n_, k_] := t[n, k] = t[n, k-1] + t[n-1, k-2]; t[n_, 0] := t[n, 0] = t[n-1, 2n-2]; t[n_, 1] := t[n, 0]; t[0, 0] = 1; Flatten[ Table[t[n, k], {n, 0, 7}, {k, 0, 2 n}]] (* Jean-François Alcover, Jun 18 2012 *)
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T(n,k)=local(A=[1]);if(2*n
Original entry on oeis.org
1, 1, 3, 10, 43, 216, 1241, 7988, 56763, 440254, 3693728, 33281359, 320112326, 3270177860, 35329070470, 402128329243, 4806784533967, 60166803598106, 786622663286330, 10717555856584617, 151864784070048105
Offset: 0
-
a(n):=if n=0 then 1 else sum(sum(binomial(i-1,k-1)*binomial(i,n-i),i,k,n)*a(k-1),k,1,n); /* Vladimir Kruchinin, May 02 2012 */
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{a(n)=local(G=1+x+x*O(x^n));for(i=0,n,G=1+x*subst(G,x,x/(1-x)^2)/(1-x)); polcoeff(subst((G-1)/x,x,x/(1+x))/(1+x),n)}
A144250
Eigentriangle, row sums = A125275, shifted.
Original entry on oeis.org
1, 1, 1, 1, 3, 2, 1, 6, 10, 6, 1, 10, 30, 42, 23, 1, 15, 70, 168, 207, 106, 1, 21, 140, 504, 1035, 1166, 567, 1, 28, 252, 1260, 3795, 6996, 7371, 3434
Offset: 0
First few rows of the triangle =
1;
1, 1;
1, 3, 2;
1, 6, 10, 6;
1, 10, 30, 42, 23;
1, 15, 70, 168, 207, 106;
1, 21, 140, 504, 1035, 1166, 567;
...
Row 4 = (1, 10, 30, 42, 23) = termwise products of (1, 10, 15, 7, 1) and (1, 1, 2, 6, 23) = (1*1, 10*1, 15*2, 7*6, 1*23); where (1, 10, 15, 7, 1) = row 4 of triangle A085478. Q
A244888
Triangle of coefficients arising in study of up-down permutations.
Original entry on oeis.org
1, -2, 1, 6, -6, 1, -23, 36, -15, 1, 106, -229, 160, -37, 1, -567, 1574, -1566, 650, -93, 1, 3434, -11706, 15248, -9310, 2572, -238, 1, -23137, 93831, -151933, 123814, -52136, 10175, -616, 1
Offset: 1
Triangle begins:
1;
-2, 1;
6, -6, 1;
-23, 36, -15, 1;
106, -229, 160, -37, 1;
-567, 1574, -1566, 650, -93, 1;
3434, -11706, 15248, -9310, 2572, -238, 1;
-23137, 93831, -151933, 123814, -52136, 10175, -616, 1;
...
Showing 1-10 of 13 results.
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