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 A143235 Triangle read by rows, A130209 * A000012 * A130209. 1
 1, 2, 4, 2, 4, 4, 3, 6, 6, 9, 2, 4, 4, 6, 4, 4, 8, 8, 12, 8, 16, 2, 4, 4, 6, 4, 8, 4, 4, 8, 8, 12, 8, 16, 8, 16, 3, 6, 6, 9, 6, 12, 6, 12, 9, 4, 8, 8, 12, 8, 16, 8, 16, 12, 16, 2, 4, 4, 6, 4, 8, 4, 8, 6, 8, 4, 6, 12, 12, 18, 12, 24, 12, 24, 18, 24, 12, 36, 2, 4, 4, 6, 4, 8, 4, 8, 6, 8, 4, 12, 4 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Row sums = A143236: (1, 6, 10, 24, 20, 56, 32,...). LINKS FORMULA Triangle read by rows, A130209 * A000012 * A130209; 1<=k<=n. T(n,k) = d(n)*d(k), where d(n) & d(k) = A000005, the number of divisors of n or k. EXAMPLE First few rows of the triangle = 1; 2, 4; 2, 4, 4; 3, 6, 6, 9; 2, 4, 4, 6, 4; 4, 8, 8, 12, 8, 16; 2, 4, 4, 6, 4, 8, 4; 4, 8, 8, 12, 8, 16, 8, 16; 3, 6, 6, 9, 6, 12, 6, 12, 9; ... T(9,6) = 12 = d(9)*d(6) = 3*4. CROSSREFS Cf. A000005, A143236. Sequence in context: A074075 A184186 A004020 * A069465 A047947 A018838 Adjacent sequences:  A143232 A143233 A143234 * A143236 A143237 A143238 KEYWORD nonn,tabl AUTHOR Gary W. Adamson, Aug 01 2008 STATUS approved

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