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 A143544 Triangle read by rows, T(n,k) = 2 if n is prime, 1 otherwise; 1<=k<=n. 1
 1, 2, 2, 2, 2, 2, 1, 1, 1, 1, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Row sums = A143545: (1, 4, 6, 4, 10, 6, 14,...) = componentwise addition of (1, 2, 3, 4, 5,...) and A061397: (0, 2, 3, 0, 5, 0, 7,...). LINKS FORMULA Triangle read by rows, T(n,k) = 2 if n is prime, 1 otherwise; 1<=k<=n EXAMPLE First few rows of the triangle = 1; 2, 2; 2, 2, 2; 1, 1, 1, 1; 2, 2, 2, 2, 2; 1, 1, 1, 1, 1, 1; 2, 2, 2, 2, 2, 2, 2; ... CROSSREFS Cf. A061397, A143545. Sequence in context: A214564 A102675 A177849 * A031346 A335808 A087472 Adjacent sequences:  A143541 A143542 A143543 * A143545 A143546 A143547 KEYWORD nonn,tabl AUTHOR Gary W. Adamson, Aug 23 2008 STATUS approved

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Last modified May 7 12:38 EDT 2021. Contains 343650 sequences. (Running on oeis4.)