login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A052166
Primes at which the difference pattern X424Y (X and Y >= 6) occurs in A001223.
2
37, 223, 307, 457, 853, 877, 1087, 1297, 1423, 1993, 2683, 4513, 4783, 5227, 6823, 7873, 8287, 10453, 13687, 13873, 16183, 17383, 20743, 21313, 23053, 23557, 23623, 24103, 27733, 29017, 31387, 33343, 33613, 35527, 36007, 37987, 40423, 42013
OFFSET
1,1
EXAMPLE
37 is here because 37 + 4 = 41, 37 + 4 + 2 = 43, 37 + 4 + 2 + 4 = 47 are consecutive primes and the prime preceding 37 is 31, the prime following 47 is 53, and the corresponding differences are 6 and 6. Thus the d-pattern "around 37" is {6,4,2,4}.
MATHEMATICA
okQ[n_List]:=Module[{d=Differences[n]}, Take[d, {2, 4}]=={4, 2, 4} && First[d]>5&&Last[d]>5]; Transpose[Select[ Partition[ Prime[ Range[ 4400]], 6, 1], okQ]][[2]] (* Harvey P. Dale, Jul 17 2011 *)
KEYWORD
nonn
AUTHOR
Labos Elemer, Jan 26 2000
STATUS
approved