cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A060232 Smaller of twin primes whose mean (average) is a multiple of A002110(6)=30030.

Original entry on oeis.org

180179, 270269, 300299, 330329, 390389, 420419, 540539, 660659, 840839, 1231229, 1261259, 1501499, 1621619, 1861859, 1921919, 1951949, 2012009, 2372369, 2762759, 2972969, 3663659, 3693689, 3723719, 3903899, 4084079
Offset: 1

Views

Author

Labos Elemer, Mar 21 2001

Keywords

Examples

			For the pair {5735729,5735731} (5735729+5735731)/2 = 191*30030.
		

Crossrefs

Programs

  • GAP
    P:=Filtered([1..10^5], IsPrime);;
    P1:=List(Filtered(Filtered(List([1..Length(P)-1], n -> [P[n],P[n+1]]),i -> i[2]-i[1]=2), j -> (j[1] + j[2]) mod 30030 = 0), k -> k[1]); # Muniru A Asiru, Jan 29 2018
  • Maple
    for n from 1 to 10^5 do if (ithprime(n+1) - ithprime(n)) = 2 and (ithprime(n+1) + ithprime(n)) mod 30030 = 0 then print(ithprime(n)); fi; od; # Muniru A Asiru, Jan 29 2018
    # More efficient:
    select(t -> isprime(t) and isprime(t+2), [seq(30030*k-1, k=1..10^3)]); # Robert Israel, Jan 29 2018
  • Mathematica
    Select[Partition[Prime[Range[300000]],2,1],#[[2]]-#[[1]]==2&&Divisible[Mean[ #],30030]&][[All,1]] (* Harvey P. Dale, Apr 23 2022 *)

Extensions

Minor edits by Ray Chandler, Apr 04 2009
Definition clarified by Harvey P. Dale, Apr 23 2022