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A076034
Group the natural numbers so that the n-th group contains the smallest set of n relatively prime numbers: (1), (2, 3), (4, 5, 7), (6, 11, 13, 17), (8, 9, 19, 23, 25), (10, 21, 29, 31, 37, 41), ...
4
1, 2, 3, 4, 5, 7, 6, 11, 13, 17, 8, 9, 19, 23, 25, 10, 21, 29, 31, 37, 41, 12, 35, 43, 47, 53, 59, 61, 14, 15, 67, 71, 73, 79, 83, 89, 16, 27, 49, 55, 97, 101, 103, 107, 109, 18, 65, 77, 113, 127, 131, 137, 139, 149, 151, 20, 33, 91, 157, 163, 167, 173, 179, 181, 191, 193
OFFSET
1,2
EXAMPLE
The triangle begins:
1;
2, 3;
4, 5, 7;
6, 11, 13, 17;
8, 9, 19, 23, 25;
10, 21, 29, 31, 37, 41;
...
MAPLE
S:=[$1..1000]: Res:= NULL:
for n from 1 to 20 do
A:= [S[1]]; R:= 1; count:= 1;
for k from 2 while count < n do
if andmap(t -> igcd(t, S[k])=1, A) then count:= count+1; A:= [op(A), S[k]]; R:= R, k; fi
od;
S:= subsop(op(map(t -> t=NULL, [R])), S);
Res:= Res, op(A);
od:
Res; # Robert Israel, Dec 04 2022
PROG
(Perl) # See Links section.
CROSSREFS
KEYWORD
nonn,tabl,look
AUTHOR
Amarnath Murthy, Oct 01 2002
EXTENSIONS
More terms from David Wasserman, Jan 29 2005
Crossrefs added by Paul Tek, Oct 24 2015
STATUS
approved