OFFSET
1,1
COMMENTS
The largest term of each row is as small as possible. Although Nowicki reports on the 28th row of this triangle, those terms are too large. Sequence A096003 reports the largest terms.
LINKS
T. D. Noe, Rows n = 1..32 of triangle, flattened
Andrzej Nowicki, Second numbers in arithmetic progressions, arxiv 1306.6424
EXAMPLE
Triangle:
4,
4, 6,
6, 10, 14,
10, 22, 34, 46,
10, 22, 34, 46, 58,
201, 205, 209, 213, 217, 221,
133, 185, 237, 289, 341, 393, 445,
133, 185, 237, 289, 341, 393, 445, 497,
635, 707, 779, 851, 923, 995, 1067, 1139, 1211,
697, 793, 889, 985, 1081, 1177, 1273, 1369, 1465, 1561
MATHEMATICA
SemiPrimeQ[n_Integer] := If[Abs[n] < 2, False, (2 == Plus @@ Transpose[FactorInteger[Abs[n]]][[2]])]; p2 = Select[Range[2000], SemiPrimeQ]; nn = Length[p2]; t = {}; n = 0; last = 1; While[n++; found = False; last = n; While[k = last - 1; While[d = p2[[last]] - p2[[k]]; nums = Table[p2[[last]] - i*d, {i, 0, n - 1}]; int = Intersection[nums, Take[p2, last]]; nums[[-1]] > 0 && Length[int] < n, k--]; nums[[-1]] <= 0 && last < nn, last++]; If[last < nn, AppendTo[t, Reverse[nums]]]; last < nn]; t
CROSSREFS
AUTHOR
T. D. Noe, Jun 28 2013
STATUS
approved