A173866 Catalan numbers that are averages of twin prime pairs.

42, 4861946401452, 637841185472509493966277041641953081675754238090104091048544721209706145413312768740

Offset

1,1

Comments

No further terms up to Catalan Number 3000, which has 1801 digits. - Harvey P. Dale, Jun 18 2021

Links

Table of n, a(n) for n=1..3.

Mathematica

f[n_]:=(2n)!/n!/(n+1)!; Select[Table[f[n], {n, 0, 6!}], PrimeQ[ #-1]&&PrimeQ[ #+1]&]
Select[CatalanNumber[Range[200]], AllTrue[#+{1, -1}, PrimeQ]&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Jun 18 2021 *)

Crossrefs

Cf. A000108, A014574

Sequence in context: A152508 A238637 A070177 * A291871 A357001 A114786

Adjacent sequences: A173863 A173864 A173865 * A173867 A173868 A173869

Keyword

nonn,bref

Author

Vladimir Joseph Stephan Orlovsky, Feb 28 2010

Status

approved