

A090870


a(n) is the smallest m such that d(m+k1)=2k for k=1,...,n where d(t)= prime(t+1)prime(t)(differences of consecutive primes in arithmetic progression).


0




OFFSET

1,1


COMMENTS

Is this sequence infinite?


LINKS

Table of n, a(n) for n=1..10.


FORMULA

a(n) = primePi(A016045(n)).


EXAMPLE

a(8)=6496152 because prime(6496152) = 113575727 and 113575727, 113575729, 113575733, 113575739, 113575747, 113575757, 113575769, 113575783, and 113575799 are nine consecutive primes with differences respectively 2, 4, 6, 8, 10, 12, 14, 16.


MATHEMATICA

a[n_] := (For[m=1, !Sum[(d[m+k1]2k)^2, {k, n}]==0, m++ ]; m); Do[Print[a[n]], {n, 8}]


CROSSREFS

Cf. A016045, A049232.
Sequence in context: A057736 A181263 A130309 * A088542 A075840 A096225
Adjacent sequences: A090867 A090868 A090869 * A090871 A090872 A090873


KEYWORD

more,nonn


AUTHOR

Farideh Firoozbakht, Dec 11 2003


EXTENSIONS

Extended and edited by T. D. Noe, May 23 2011


STATUS

approved



