A125790 Rectangular table where column k equals row sums of matrix power A078121^k, read by antidiagonals.
1, 1, 1, 1, 2, 1, 1, 4, 3, 1, 1, 10, 9, 4, 1, 1, 36, 35, 16, 5, 1, 1, 202, 201, 84, 25, 6, 1, 1, 1828, 1827, 656, 165, 36, 7, 1, 1, 27338, 27337, 8148, 1625, 286, 49, 8, 1, 1, 692004, 692003, 167568, 25509, 3396, 455, 64, 9, 1, 1, 30251722, 30251721, 5866452, 664665, 64350, 6321, 680, 81, 10, 1
Offset: 0
Examples
Recurrence T(n,k) = T(n,k-1) + T(n-1,2*k) is illustrated by: T(4,3) = T(4,2) + T(3,6) = 201 + 455 = 656; T(5,3) = T(5,2) + T(4,6) = 1827 + 6321 = 8148; T(6,3) = T(6,2) + T(5,6) = 27337 + 140231 = 167568. Rows of this table begin: 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, ...; 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, ...; 1, 4, 9, 16, 25, 36, 49, 64, 81, 100, 121, 144, 169, ...; 1, 10, 35, 84, 165, 286, 455, 680, 969, 1330, 1771, 2300, ...; 1, 36, 201, 656, 1625, 3396, 6321, 10816, 17361, 26500, 38841, ...; 1, 202, 1827, 8148, 25509, 64350, 140231, 274856, 497097, ...; 1, 1828, 27337, 167568, 664665, 2026564, 5174449, 11622976, ...; 1, 27338, 692003, 5866452, 29559717, 109082974, 326603719, ...; 1, 692004, 30251721, 356855440, 2290267225, 10243585092, ...; ... Triangle A078121 begins: 1; 1, 1; 1, 2, 1; 1, 4, 4, 1; 1, 10, 16, 8, 1; 1, 36, 84, 64, 16, 1; 1, 202, 656, 680, 256, 32, 1; ... where row sums form column 1 of this table A125790, and column k of A078121 equals column 2^k-1 of this table A125790. Matrix cube A078121^3 begins: 1; 3, 1; 9, 6, 1; 35, 36, 12, 1; 201, 286, 144, 24, 1; 1827, 3396, 2300, 576, 48, 1; ... where row sums form column 3 of this table A125790, and column 0 of A078121^3 forms column 2 of this table A125790.
Links
- G. Blom and C.-E. Froeberg, Om myntvaexling (On money-changing) [Swedish], Nordisk Matematisk Tidskrift, 10 (1962), 55-69, 103. [Annotated scanned copy] See Table 5.
Crossrefs
Programs
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Mathematica
T[n_, k_] := T[n, k] = T[n, k-1] + T[n-1, 2*k]; T[0, ] = T[, 0] = 1; Table[T[n-k, k], {n, 0, 10}, {k, 0, n}] // Flatten (* Jean-François Alcover, Jun 15 2015 *)
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PARI
{T(n,k,p=0,q=2)=local(A=Mat(1), B); if(n
Formula
T(n,k) = T(n,k-1) + T(n-1,2*k) for n>0, k>0, with T(0,n)=T(n,0)=1 for n>=0.
Conjecture: g.f. for n-th row is (Sum_{i=0..n-1} x^i Sum_{j=0..i} binomial(n+1,j)*T(n,i-j)*(-1)^j)/(1-x)^(n+1) for n > 0. - Mikhail Kurkov, May 03 2025
Comments