

A089180


a(n) is the smallest number m such that d(m) = d(m+1) = ... = d(m+n), where d(k) = prime(k+1)prime(k) (A001223).


1




OFFSET

1,1


COMMENTS

a(5) is greater than 105000000.
The a(n)th prime is the smallest start of n+2 consecutive primes in arithmetic progression.  Jens Kruse Andersen, Jun 14 2014


LINKS

Table of n, a(n) for n=1..4.
J. K. Andersen, The minimal CPAPk.
L. J. Lander and T. R. Parkin, Consecutive primes in arithmetic progression, Math. Comp. vol 21 no 99 (1967) p 489.
G. W. Polites, Prime Desert nTuplets, Amer. Math. Monthly vol 95 no 2 (1988) p 98104.


FORMULA

A000040[a(n)]=A006560(n+2).  R. J. Mathar, Aug 10 2007
a(n) = A000720(A006560(n+2)).  Jens Kruse Andersen, Jun 14 2014


EXAMPLE

a(3) = 659426 because d(659426) = d(659426+1) = d(659426+2) = d(6594286+3) or 9843019, 9843049, 9843079, 9843109, 9843139 are five consecutive primes with same difference and prime(659426) = 9843019 is the smallest prime number with this property.
Also a(4) = 6904737 because d(6904737) = d(6904737+1) = ... = d(6904737+4) or 121174811, 121174841, 121174871, 121174901, 121174931, 121174961 are six consecutive primes with same difference and prime(6904737) = 121174811 is the smallest prime number with this property.


CROSSREFS

Cf. A001223, A090403.
Sequence in context: A283678 A117681 A221603 * A280209 A034013 A157262
Adjacent sequences: A089177 A089178 A089179 * A089181 A089182 A089183


KEYWORD

more,nonn


AUTHOR

Farideh Firoozbakht, Dec 07 2003


STATUS

approved



