login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A288022 Prime p1 of consecutive primes p1, p2, where p2 - p1 = 6, and p1, p2 are in different decades. 4
47, 157, 167, 257, 367, 557, 587, 607, 647, 677, 727, 947, 977, 1097, 1117, 1187, 1217, 1367, 1657, 1747, 1777, 1907, 1987, 2207, 2287, 2417, 2467, 2677, 2837, 2897, 2957, 3307, 3407, 3607, 3617, 3637, 3727, 3797, 4007, 4357, 4457, 4507, 4597, 4657, 4937, 4987 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The unit digits of the numbers in the sequence are 7's.

Number of terms < 10^k: 0, 0, 1, 13, 81, 565, 4027, 30422, 237715, ... - Muniru A Asiru, Jan 09 2018

LINKS

Muniru A Asiru, Table of n, a(n) for n = 1..10000

EXAMPLE

47 is in the sequence since pair (47,53) is the first with difference 6 spanning a multiple of 10.

MAPLE

for n from 1 to 2000 do if [ithprime(n+1)-ithprime(n), ithprime(n) mod 5] = [6, 2] then print(ithprime(n)); fi; od; # Muniru A Asiru, Jan 19 2018

MATHEMATICA

a288022[n_] := Map[Last, Select[Map[{NextPrime[#, 1], NextPrime[#, -1]}&, Range[10, n, 10]], First[#]-Last[#]==6&]]

a288022[3000] (* data *)

PROG

(GAP)

P:=Filtered([1..20000], IsPrime);

P1:=List(Filtered(Filtered(List([1..Length(P)-1], n->[P[n], P[n+1]]), i->i[2]-i[1]=6), j->j[1] mod 5=2), k->k[1]); # Muniru A Asiru, Jul 08 2017

CROSSREFS

Cf. A001359, A023201, A023203, A031924, A031925, A031928, A046117, A046132, A158277, A158861, A160370, A160440, A160500, A287049, A287050, A060229, A288021, A288024.

Sequence in context: A142505 A047948 A142529 * A142634 A140641 A141994

Adjacent sequences:  A288019 A288020 A288021 * A288023 A288024 A288025

KEYWORD

nonn

AUTHOR

Hartmut F. W. Hoft, Jun 04 2017

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 20 09:06 EDT 2021. Contains 348099 sequences. (Running on oeis4.)