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 A104447 Column 1 of triangular matrix A104446. 1
 1, 2, 5, 13, 39, 139, 587, 2897, 16462, 106301, 771313, 6228073, 55494336, 541651873, 5753940704, 66147591142, 818802488476, 10864622564915, 153914784829775, 2319599022540318, 37068215129072522, 626279667948552452 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS A104446 equals the square of triangular matrix A104445, read by rows, where X=A104445 satisfies: SHIFT_LEFT_UP(X) = X^2 - X + I. LINKS FORMULA a(n) = A091352(n-1) + A091353(n-1). PROG (PARI) a(n)=local(A=Mat(1), B); for(m=1, n+1, B=A^2-A+A^0; A=matrix(m+1, m+1); for(i=1, m+1, for(j=1, i, if(i<2 || j==i, A[i, j]=1, if(j==1, A[i, j]=1, A[i, j]=B[i-1, j-1]))))); return((A^2)[n+2, 2]) CROSSREFS Cf. A104446, A091352, A091353. Sequence in context: A332415 A149861 A148305 * A127986 A255600 A320809 Adjacent sequences:  A104444 A104445 A104446 * A104448 A104449 A104450 KEYWORD nonn AUTHOR Paul D. Hanna, Mar 08 2005 STATUS approved

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Last modified February 25 04:57 EST 2020. Contains 332217 sequences. (Running on oeis4.)