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A173866 Catalan numbers that are averages of twin prime pairs. 0
42, 4861946401452, 637841185472509493966277041641953081675754238090104091048544721209706145413312768740 (list; graph; refs; listen; history; text; internal format)
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

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Last modified February 2 15:49 EST 2023. Contains 360022 sequences. (Running on oeis4.)