This site is supported by donations to The OEIS Foundation.

 Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing. Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A064984 Triangle of coefficients T[n,m] of polynomials n, n^2, (n+2n^3)/3, n^2(2+n^2)/3, n(3+10n^2+2n^4)/15, etc. after multiplication by the denominators (A049606). 0
 1, 0, 1, 1, 0, 2, 0, 2, 0, 1, 3, 0, 10, 0, 2, 0, 23, 0, 20, 0, 2, 45, 0, 196, 0, 70, 0, 4, 0, 132, 0, 154, 0, 28, 0, 1, 315, 0, 1636, 0, 798, 0, 84, 0, 2, 0, 5067, 0, 7180, 0, 1806, 0, 120, 0, 2, 14175, 0, 83754, 0, 50270, 0, 7392, 0, 330, 0, 4, 0, 146430, 0, 239327, 0, 74800, 0 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,6 COMMENTS These polynomials are P(1, n) = 2*Sum[k, {k,1,n-1}] + n, counting up to n and down again; P(2, m) = 2*Sum[P(1,n), {n,1,m-1}] + P(1,m), meaning up and down to n and this for n from 1 up to m and down again; etc. LINKS EXAMPLE 1+2+3+2+1 = 3^2, (1)+(1+2+1)+(1+2+3+2+1)+(1+2+1)+(1) = (n+2n^3)/3. MATHEMATICA CoefficientList[ #, n ]&/@(NestList[ ((2*Sum[ #, {n, k-1} ]+(#/. n->k)//Simplify)/.k->n)&, n, -1+16 ] Denominator[ 2^#/#!&/@Range[ 16 ] ]) CROSSREFS Row sums give A049606 again, final entry in each row seems to give A048896. Sequence in context: A268189 A265247 A022879 * A323226 A307197 A328949 Adjacent sequences:  A064981 A064982 A064983 * A064985 A064986 A064987 KEYWORD nonn,tabl AUTHOR Wouter Meeussen, Oct 30 2001 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 5 10:45 EST 2019. Contains 329751 sequences. (Running on oeis4.)