A075872 a(n) = binomial(prime(n),n)/prime(n) where prime(n) = n-th prime.

1, 1, 2, 5, 42, 132, 1144, 3978, 35530, 690690, 2731365, 50067108, 429757960, 1822766520, 15991836267, 280086337895, 4703540164785, 21512315482350, 360471372561300, 3174207914954076, 14859478810664136, 248599618581498860, 2209822117125283440, 36246606227404101045

Offset: 1

Author

Lekraj Beedassy, Oct 16 2002

Keywords

• nonn

Comments

A prime p divides all the entries (binomial coefficients) in the p-th row of Pascal's triangle.

Crossrefs

Cf. A060604, A000040.

Programs

Maple

seq(binomial(ithprime(n),n)/ithprime(n),n=1..30);

Mathematica

f[n_]:=Module[{pn=Prime[n]},Binomial[pn,n]/pn]
f/@Range[30]  (* Harvey P. Dale, Feb 25 2011 *)

PARI

a(n) = my(p=prime(n)); binomial(p, n)/p; \\ Michel Marcus, Jul 15 2022

Formula

a(n) = A060604(n)/A000040(n).

Extensions

More terms from Emeric Deutsch, Mar 04 2004