0,2

Row 0 of table represents "mod 2 prime signature" values k such that no PPTs have leg=k.

Row n of table, n>0, represents "mod 2 prime signature" values k such that 2^(n-1) PPTs have leg=k. Table read by antidiagonals.

For n=2^a_0*p_1^a_1*...*p_n^a_n where p_i is odd prime and a_1>=a_2>=...>=a_n, define "mod 2 prime signature" to be ordered prime exponents (a_0,a_1,...,a_n).

Least integer with a given "mod 2 prime signature" is obtained by replacing p_1 with 3, p_2 with 5,..., p_n with n-th odd prime.

Eric Weisstein's World of Mathematics, Pythagorean Triple.

Table begins:

0: 1,2,6,18,30,54,90,162,210,270,...

1: 3,4,8,9,16,27,32,64,81,128,...

2: 12,15,24,36,45,48,72,96,108,135,...

4: 60,105,120,180,240,315,360,480,540,720,...

8: 420,840,1155,1260,1680,2520,3360,3465,3780,5040,...

16: 4620,9240,13860,15015,18480,27720,36960,41580,45045,55440,...

32: 60060,120120,180180,240240,255255,360360,480480,540540,...

64: 1021020,2042040,3063060,4084080,4849845,6126120,8168160,...

128: 19399380,38798760,58198140,77597520,111546435,116396280,...

256: 446185740,892371480,1338557220,1784742960,2677114440,...

Cf. A097272, A097273, A097274.

Row 1 is A006899 except for starting point.

Sequence in context: A104663 A046202 A122866 this_sequence A130879 A119741 A126063

Adjacent sequences: A097272 A097273 A097274 this_sequence A097276 A097277 A097278

nonn,tabl

Ray Chandler (rayjchandler(AT)sbcglobal.net), Aug 22 2004