0,2

With a different offset, number of n-permutations (n>=9) of 6 objects: t, u, v, z, x, y with repetition allowed, containing exactly nine (9) u's.

Example: a(1)=50 because we have

uuuuuuuuut, uuuuuuuuuv, uuuuuuuuuz, uuuuuuuuux, uuuuuuuuuy,

uuuuuuuutu, uuuuuuuuvu, uuuuuuuuzu, uuuuuuuuxu, uuuuuuuuyu,

uuuuuuutuu, uuuuuuuvuu, uuuuuuuzuu, uuuuuuuxuu, uuuuuuuyuu,

uuuuuutuuu, uuuuuuvuuu, uuuuuuzuuu, uuuuuuxuuu, uuuuuuyuuu,

uuuuutuuuu, uuuuuvuuuu, uuuuuzuuuu, uuuuuxuuuu, uuuuuyuuuu,

uuuutuuuuu, uuuuvuuuuu, uuuuzuuuuu, uuuuxuuuuu, uuuuyuuuuu,

uuutuuuuuu, uuuvuuuuuu, uuuzuuuuuu, uuuxuuuuuu, uuuyuuuuuu,

uutuuuuuuu, uuvuuuuuuu, uuzuuuuuuu, uuxuuuuuuu, uuyuuuuuuu,

utuuuuuuuu, uvuuuuuuuu, uzuuuuuuuu, uxuuuuuuuu. uyuuuuuuuu,

tuuuuuuuuu, vuuuuuuuuu, zuuuuuuuuu, xuuuuuuuuu. yuuuuuuuuu.

seq(binomial(n+9, 9)*5^n, n=0..20);

(Other) SAGE:[lucas_number2(n, 5, 0)*binomial(n, 9)/5^9 for n in xrange(9, 26)] # [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Mar 12 2009]

Sequence in context: A017766 A035720 A017713 this_sequence A114251 A004351 A159177

Adjacent sequences: A140517 A140518 A140519 this_sequence A140521 A140522 A140523

nonn

Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Jul 02 2008