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 A092557 Triangle read by rows: T(1,1) = 1; for n>=2, write the first n^2 integers in an n X n array beginning with 1 in the upper left proceeding left to right and top to bottom; then T(n,k) is the last prime in the k-th row. 3
 1, 2, 3, 3, 5, 7, 3, 7, 11, 13, 5, 7, 13, 19, 23, 5, 11, 17, 23, 29, 31, 7, 13, 19, 23, 31, 41, 47, 7, 13, 23, 31, 37, 47, 53, 61, 7, 17, 23, 31, 43, 53, 61, 71, 79, 7, 19, 29, 37, 47, 59, 67, 79, 89, 97, 11, 19, 31, 43, 53, 61, 73, 83, 97, 109, 113, 11, 23, 31, 47, 59, 71, 83, 89 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS There is a prime in each row. REFERENCES Paulo Ribenboim, "The Little Book Of Big Primes," Springer-Verlag, NY 1991, page 185. LINKS EXAMPLE Triangle begins 1; 2, 3; 3, 5, 7; 3, 7, 11, 13; 5, 7, 13, 19, 23; MATHEMATICA PrevPrim[n_] := Block[{k = n - 1}, While[ !PrimeQ[k], k-- ]; k]; Table[ PrevPrim[i*n + 1], {n, 2, 12}, {i, 1, n}] CROSSREFS Cf. A092556, A083415. Sequence in context: A218932 A056878 A270520 * A333295 A144680 A081493 Adjacent sequences:  A092554 A092555 A092556 * A092558 A092559 A092560 KEYWORD nonn,tabl AUTHOR Robert G. Wilson v, Feb 27 2004 STATUS approved

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Last modified April 19 00:18 EDT 2021. Contains 343098 sequences. (Running on oeis4.)