[seqfan] a(n) + (next digit) = even or odd

[Eric Angelini]

Hello SeqFans,
I guess this is the lexico-first permutation P
of the integers > 0 where a(n) + (the next digit of P)
is even:
P = 1,3,5,7,9,10,2,4,6,8,20,21,11,12,22,23,13,14,24,25,15,16,26,27,17,18,28,29,19,30,40,41,31,32,...

Similarily, Q should be the lexico-first
permutation of the integers > 0 where
a(n) + (next digit of Q) is odd:
Q=1,2,3,4,5,6,7,8,9,20,10,11,21,22,12,13,23,24,14,15,25,26,16,17,27,28,18,19,29,40,30,31,...

Best,
É.