A019510 - OEIS

A019510

a(n) = gcd( binomial(n+3, n) + binomial(n+4, n+1), binomial(n+5, n+2) ).

2, 5, 1, 7, 20, 3, 5, 11, 2, 65, 7, 5, 8, 17, 15, 19, 10, 7, 11, 115, 4, 25, 13, 9, 70, 29, 5, 31, 16, 55, 17, 35, 6, 37, 95, 13, 20, 41, 7, 215, 22, 15, 23, 47, 40, 49, 25, 17, 26, 265

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

G. C. Greubel, Table of n, a(n) for n = 1..5000

MATHEMATICA

Table[GCD[Binomial[n+3, n]+Binomial[n+4, n+1], Binomial[n+5, n+2]], {n, 70}] (* Harvey P. Dale, Nov 16 2014 *)

PROG

(PARI) {a(n) = gcd(binomial(n+3, n)+binomial(n+4, n+1), binomial(n+5, n+2))}; \\ G. C. Greubel, Mar 24 2019

(Magma) [GCD(Binomial(n+3, n)+Binomial(n+4, n+1), Binomial(n+5, n+2)): n in [1..60]]; // G. C. Greubel, Mar 24 2019

(Sage) [gcd(binomial(n+3, n)+binomial(n+4, n+1), binomial(n+5, n+2)) for n in (1..60)] # G. C. Greubel, Mar 24 2019

CROSSREFS

Cf. A000292.

Sequence in context: A246169 A258067 A240241 * A124576 A283556 A340198

Adjacent sequences: A019507 A019508 A019509 * A019511 A019512 A019513

KEYWORD

nonn

AUTHOR

David Penney (david(AT)alpha.math.uga.edu)

STATUS

approved