A321373
Array T(n,k) read by antidiagonals where the first row is (-1)^k*A140966(k) and each subsequent row is obtained by adding A001045(k) to the preceding one.
Original entry on oeis.org
2, 2, -1, 2, 0, 3, 2, 1, 4, 1, 2, 2, 5, 4, 7, 2, 3, 6, 7, 12, 9, 2, 4, 7, 10, 17, 20, 23, 2, 5, 8, 13, 22, 31, 44, 41, 2, 6, 9, 16, 27, 42, 65, 84, 87, 2, 7, 10, 19, 32, 53, 86, 127, 172, 169, 2, 8, 11, 22, 37, 64, 107, 170, 257, 340, 343
Offset: 0
Triangle a(n):
2;
2, -1;
2, 0, 3;
2, 1, 4, 1;
2, 2, 5, 4, 7;
2, 3, 6, 7, 12, 9;
2, 4, 7, 10, 17, 20, 23;
etc.
Row sums: 2, 1, 5, 8, 20, 39, 83, 166, 338, 677, 1361, 2724, ... = b(n+2).
With b(0) = 2 and b(1) = 0, b(n) = b(n-1) + 2*b(n-2) + n - 4, n > 1.
b(n) = A001045(n) - A097065(n-1).
b(n) = b(n-2) + A000225(n-2).
Cf.
A000079,
A001045,
A014113,
A014551,
A048573,
A062092,
A078008,
A084247,
A092297,
A097073,
A140360,
A140966.
-
T[_, 0] = 2;
T[0, k_] := (2^k + 5(-1)^k)/3;
T[n_ /; n>0, k_ /; k>0] := T[n, k] = T[n-1, k] + (2^k + (-1)^(k+1))/3;
T[, ] = 0;
Table[T[n-k, k], {n, 0, 10}, {k, 0, n}] // Flatten (* Jean-François Alcover, Nov 10 2018 *)
A328881
a(n+3) = 2^n - a(n), a(0)=a(2)=1, a(1)=0 for n >= 0.
Original entry on oeis.org
1, 0, 1, 0, 2, 3, 8, 14, 29, 56, 114, 227, 456, 910, 1821, 3640, 7282, 14563, 29128, 58254, 116509, 233016, 466034, 932067, 1864136, 3728270, 7456541, 14913080, 29826162, 59652323, 119304648, 238609294, 477218589, 954437176, 1908874354, 3817748707
Offset: 0
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a[0] = a[2] = 1; a[1] = 0; a[n_] := a[n] = 2^(n - 3) - a[n - 3]; Array[a, 36, 0] (* Amiram Eldar, Nov 06 2019 *)
-
Vec((1 - 2*x + x^2 - x^3) / ((1 + x)*(1 - 2*x)*(1 - x + x^2)) + O(x^40)) \\ Colin Barker, Oct 29 2019
A360033
Table T(n,k), n >= 1 and k >= 0, read by antidiagonals, related to Jacobsthal numbers A001045.
Original entry on oeis.org
1, 2, 1, 3, 3, 3, 4, 5, 7, 5, 5, 7, 11, 13, 11, 6, 9, 15, 21, 27, 21, 7, 11, 19, 29, 43, 53, 43, 8, 13, 23, 37, 59, 85, 107, 85, 9, 15, 27, 45, 75, 117, 171, 213, 171, 10, 17, 31, 53, 91, 149, 235, 341, 427, 341, 11, 19, 35, 61, 107, 181, 299, 469
Offset: 1
The array T(n,k), for n <= 1 and k >= 0, begins:
n = 1: 1, 1, 3, 5, 11, 21, 43, ... -> A001045(k+1)
n = 2: 2, 3, 7, 13, 27, 53, 107, ... -> A048573(k)
n = 3: 3, 5, 11, 21, 43, 85, 171, ... -> A001045(k+3)
n = 4: 4, 7, 15, 29, 59, 117, 235, ... -> ?
n = 5: 5, 9, 19, 37, 75, 149, 299, ... -> A062092(k+1)
n = 6: 6, 11, 23, 45, 91, 181, 363, ... -> ?
n = 7: 7, 13, 27, 53, 107, 213, 427, ... -> A048573(k+2)
Comments