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A124265
Variant sequence generated by solving the order n x n linear problem [H]x = b where b is the unit vector and the sequence term is given by the denominator of the last unknown xn.
0
3, 3, 11, 27, 162, 380, 7650, 17325, 81340, 2518992, 91128240, 424947600, 14078156400, 33300661680, 424624548348
OFFSET
1,1
FORMULA
[H] is defined by hilbertWarrenA1[i,j]:=(1+j+i)/(-1+j+i) where numbering starts at 1.
PROG
HilbertWarren(fun, order) := ( Unity[i, j] := 1, A : genmatrix(fun, order, order), B : genmatrix(Unity, 1, order), App : invert(triangularize(A)), Xp : App . B, 1/Xp[order] ); findWarrenSequenceTerms(fun, a, b) := ( L : append(), for order: a next order+1 through b do L: cons(first(HilbertWarren(fun, order)), L), S : reverse(L) ); k : 15; hilbert[i, j] := 1/(i + j - 1); findWarrenSequenceTerms(hilbert, 1, k); hilbertA0[i, j] := (i + j + 0)/(i + j - 1); /* sum 1 */ findWarrenSequenceTerms(hilbertA0, 1, k); hilbertA1[i, j] := (i + j + 1)/(i + j - 1); /* sum 2: there are lots of these, increment numerator */ findWarrenSequenceTerms(hilbertA1, 1, k); hilbertD1[i, j] := (i - j + 1)/(i + j - 1); /* difference 1 */ findWarrenSequenceTerms(hilbertD1, 1, k); hilbertP1[i, j] := (i * j + 0)/(i + j - 1); /* product 1 */ findWarrenSequenceTerms(hilbertP1, 1, k); hilbertQ1[i, j] := (i / j)/(i + j - 1); /* quotient 1 */ findWarrenSequenceTerms(hilbertQ1, 1, k);
CROSSREFS
Sequence in context: A281101 A341601 A322701 * A163938 A373393 A109937
KEYWORD
eigen,frac,hard,nonn
AUTHOR
L. Van Warren (van(AT)wdv.com), Oct 23 2006
STATUS
approved