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A209063 Let p = A099180(n) be the n-th prime which is greater than its reversal p'; a(n) = number of ways to write p as a multiple of p' +- q where q is a prime < p. 6

%I #21 Jan 27 2021 10:35:37

%S 1,2,0,1,4,3,0,2,1,1,1,1,1,1,0,0,3,2,4,0,0,2,0,2,1,3,1,1,1,1,1,4,1,4,

%T 2,0,1,2,1,1,1,2,1,0,1,1,1,4,4,1,0,1,1,2,0,3,2,0,0,3,1,3,0,0,1,3,0,0,

%U 2,1,0,1,0,0,1,1,0,1,1,0,0,0,0,0,1,0,1,1,1,1,0,1,1,1,0,0,1,1,0,1,1,1

%N Let p = A099180(n) be the n-th prime which is greater than its reversal p'; a(n) = number of ways to write p as a multiple of p' +- q where q is a prime < p.

%C Sequence is bounded - see A202286.

%F Equals A209914 o A099180. - _M. F. Hasler_, Mar 15 2012

%e For n=6, p = 71, p' = 17 and there are three solutions:

%e 71 = 2*17 + 3771 = 4*17 + 371 = 6*17 - 31, so a(6) = 3.

%o (PARI) A209063(n)=A209914(A099180(n)) \\ _M. F. Hasler_, Mar 15 2012

%Y Cf. A099180, A209914. A202286 gives smallest m such that a(m) = n.

%K nonn,base

%O 1,2

%A _N. J. A. Sloane_, Mar 13 2012

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Last modified April 23 11:35 EDT 2024. Contains 371912 sequences. (Running on oeis4.)