[seqfan] [a(n) + next digit of S] = prime

Eric Angelini Eric.Angelini at kntv.be
Fri Nov 14 12:02:30 CET 2014


Hello SeqFans,
a(1)=1
a(n) is the smallest integer not yet in S and not stopping S,
such that a(n-1) + [the leftmost digit of a(n)] is prime.

S = 1,2,3,4,7,6,5,8,9,20,30,10,11,21,22,31,... 

S is not a permutation of the integers > 0 (as 113, for instance,
cannot be followed by anything; so 113 is forbidden in S)

Best,
É.



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