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.
J. W. Helkenberg has authored 35 sequences. Here are the ten most recent ones:
Select[Range[0, 400], PrimeQ[90# +91]&]
isA224889(n) = isprime(90*n + 91) \\ Michael B. Porter, Jul 28 2013
Select[Range[0, 499], PrimeQ[90# + 47] && PrimeQ[90# + 49] &] (* copied from: Alonso del Arte, Jul 22 2013 *) Select[Range[500],AllTrue[90#+{47,49},PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Oct 18 2015 *)
Select[Range[0, 499], PrimeQ[90# + 77] && PrimeQ[90# + 79] &] (* copied from: Alonso del Arte, Jul 22 2013 *) Select[Range[500],AllTrue[90#+{77,79},PrimeQ]&] (* Harvey P. Dale, Mar 19 2023 *)
Select[Range[0, 499], PrimeQ[90# + 71] && PrimeQ[90# + 73] &] (* copied from: Alonso del Arte, Jul 22 2013 *)
a:= proc(n) option remember; local k; for k from 1+
`if`(n=1, -1, a(n-1)) while not (isprime(29+(90*k))
and isprime(31+(90*k))) do od; k
end:
seq(a(n), n=1..100); # Alois P. Heinz, Jul 23 2013
Select[Range[0, 499], PrimeQ[90# + 29] && PrimeQ[90# + 31] &] (* copied from: Alonso del Arte, Jul 22 2013 *)
Select[Range[0, 499], PrimeQ[90# + 17] && PrimeQ[90# + 19] &] (* Copied from: Alonso del Arte, Jul 22 2013 *)
Select[Range[0, 499], PrimeQ[90# + 11] && PrimeQ[90# + 13] &]
Select[Range[0, 499], PrimeQ[90# + 41] && PrimeQ[90# + 43] &] (* Alonso del Arte, Jul 22 2013 *)
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