

A110194


First differences of A110095 (least nonprime sequence whose first differences are nonprime).


0



1, 8, 1, 4, 1, 1, 4, 1, 1, 4, 1, 1, 4, 1, 1, 1, 1, 4, 4, 1, 1, 4, 1, 1, 4, 1, 1, 4, 1, 1, 1, 1, 4, 4, 1, 1, 1, 1, 4, 4, 1, 1, 4, 1, 1, 1, 1, 4, 4
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OFFSET

1,2


COMMENTS

Conjecture: from a(5) on, are there only substrings <1 1 4> and <1 1 1 1 4 4 >?


LINKS

Table of n, a(n) for n=1..49.


EXAMPLE

Beginning with 1, we have to add 8 in order to get the first nonprime number (all other numbers <8 are prime or giving a prime). So 1+8=9 for a(2).
Then add 1=10 for a(3).
Then add (not 1 because 11 is prime; nor 2 and 3 because they are prime) ...add 4=14 for a(4), etc.


CROSSREFS

Cf. A110095 and twinprimes related sequences.
Sequence in context: A011469 A140457 A176457 * A199283 A079359 A010156
Adjacent sequences: A110191 A110192 A110193 * A110195 A110196 A110197


KEYWORD

easy,nonn


AUTHOR

Alexandre Wajnberg & Eric Angelini, Sep 06 2005


STATUS

approved



