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 A168261 Triangle read by rows, A115361 * the diagonalized variant of A018819. 2
 1, 1, 1, 0, 0, 2, 1, 1, 0, 2, 0, 0, 0, 0, 4, 0, 0, 2, 0, 0, 4, 0, 0, 0, 0, 0, 0, 6, 1, 1, 0, 2, 0, 0, 0, 6, 0, 0, 0, 0, 0, 0, 0, 0, 10, 0, 0, 0, 0, 4, 0, 0, 0, 0, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 14, 0, 0, 2, 0, 0, 4, 0, 0, 0, 0, 0, 14, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 20 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,6 COMMENTS Row sums = A018819 starting with offset 1; (1, 2, 2, 4, 4, 6, 6, 10, 10,...). = the eigensequence of triangle A115361. Rightmost diagonal = A018819 Sum of n-th row terms = rightmost term of next row. LINKS FORMULA Let M = triangle A115361, and Q = the diagonalized variant of A018819 such that (1, 1, 2, 2, 4, 4, 6, 6,...) = rightmost diagonal with the rest zeros. Triangle A168261 = M*Q as infinite lower triangular matrices. EXAMPLE First few rows of the triangle = 1; 1, 1; 0, 0, 2; 1, 1, 0, 2; 0, 0, 0, 0, 4; 0, 0, 2, 0, 0, 4; 0, 0, 0, 0, 0 0, 6; 1, 1, 0, 2, 0, 0, 0, 6; 0, 0, 0, 0, 0, 0, 0, 0, 10; 0, 0, 0, 0, 4, 0, 0, 0, 0, 10; 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 14; 0, 0, 2, 0, 0, 4, 0, 0, 0, 0, 0, 14; 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 20; 0, 0, 0, 0, 0, 0, 6, 0, 0, 0, 0, 0, 0, 20; 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 26; 1, 1, 0, 2, 0, 0, 0, 6, 0, 0, 0, 0, 0, 0, 0, 26; 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 36; ... CROSSREFS Cf. A115361, A018819 Sequence in context: A152459 A275784 A097608 * A180997 A143439 A105469 Adjacent sequences:  A168258 A168259 A168260 * A168262 A168263 A168264 KEYWORD nonn,tabl AUTHOR Gary W. Adamson, Nov 21 2009 STATUS approved

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Last modified February 16 20:45 EST 2019. Contains 320189 sequences. (Running on oeis4.)