A072286 Denominators of inverse unimodal analog of binomial coefficients: binomial(n,m) = Sum_{k=0..n-m} a(2*k+m-1, 2*k).

1, 1, 1, 1, 2, 1, 1, 8, 1, 1, 1, 16, 1, 2, 1, 1, 128, 1, 8, 1, 1, 1, 256, 1, 16, 1, 2, 1, 1, 1024, 1, 128, 1, 8, 1, 1, 1, 2048, 1, 256, 1, 16, 1, 2, 1, 1, 32768, 1, 1024, 1, 128, 1, 8, 1, 1, 1, 65536, 1, 2048, 1, 256, 1, 16, 1, 2, 1, 1, 262144, 1, 32768, 1, 1024, 1, 128, 1, 8, 1, 1

Offset

0,5

Comments

Entries are powers of 2.

Links

G. C. Greubel, Rows n = 0..100 of triangle, flattened

Formula

a(n, m) = binomial(n-m/2+1, n-m+1) - binomial(n-m/2, n-m+1).

Mathematica

a[n_, m_]:= Binomial[n -m/2 +1, n-m+1] - Binomial[n -m/2, n-m+1]; Flatten[Table[Denominator[a[n, m]], {n, 0, 11}, {m, 0, n}]]

Prog

(PARI) a(n, m) = binomial(n-m/2, n-m);
for(n=0, 11, for(m=0, n, print1(denominator(a(n, m)), ", "))) \\ G. C. Greubel, Aug 26 2019
(Sage) [[denominator( binomial(n-m/2, n-m) ) for m in (0..n)] for n in (0..11)] # G. C. Greubel, Aug 26 2019

Crossrefs

Cf. A072285, A071922.

Sequence in context: A058955 A176055 A354986 * A007375 A294808 A294605

Adjacent sequences: A072283 A072284 A072285 * A072287 A072288 A072289

Keyword

nonn,easy,frac,tabl

Author

Michele Dondi (bik.mido(AT)tiscalinet.it), Jul 11 2002

Status

approved