A110552 A triangular array related to A077028 and distributing the values of A007582.
1, 1, 2, 1, 5, 4, 1, 10, 17, 8, 1, 19, 51, 49, 16, 1, 36, 134, 196, 129, 32, 1, 69, 330, 650, 645, 321, 64, 1, 134, 783, 1940, 2575, 1926, 769, 128, 1, 263, 1813, 5411, 8995, 8981, 5383, 1793, 256, 1, 520, 4124, 14392, 28742, 35896, 28700, 14344, 4097, 512, 1, 1033, 9252, 36948, 86142, 129150, 129108, 86052, 36873, 9217, 1024
Offset: 1
Examples
The filled templates begin 1 .1 .2 ..1 ..2.3 ..4 ....1 ....2.3.5 ....4.6.7 ....8 therefore the sequence begins 1 1 2 1 5 4 1 10 17 8 ...
Links
- G. C. Greubel, Table of n, a(n) for the first 50 rows, flattened
- P. Barry, A Note on a Family of Generalized Pascal Matrices Defined by Riordan Arrays, Journal of Integer Sequences, 16 (2013), #13.5.4.
Programs
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Mathematica
T[n_, k_] := Binomial[n - 2, k - 1] + 2^(n - 1)*Binomial[n - 2, k - 2]; Table[T[n, k], {n, 1, 20}, {k, 1, n}] // Flatten (* G. C. Greubel, Aug 31 2017 *)
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PARI
for(n=1,20, for(k=1,n, print1(binomial(n - 2, k - 1) + 2^(n - 1)*binomial(n - 2, k - 2), ", "))) \\ G. C. Greubel, Aug 31 2017
Formula
Table entries appear to be given by T(n,k) = binomial(n-2,k-1) + 2^(n-1)*binomial(n-2,k-2), n,k >= 1, leading to the e.g.f. (exp((1+x)*u) - 1)*(x*exp((1+x)*u) + x + 2)/(2*(1+x)^2) = u + (1+2*x)*u^2/2! + (1+5*x+4*x^2)*u^3/3! + .... Cf. A111049. - Peter Bala, Jul 27 2012
Comments