This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A147703 Triangle [1,1,1,0,0,0,...] DELTA [1,0,0,0,.....] with Deléham DELTA defined in A084938. 28
 1, 1, 1, 2, 3, 1, 5, 9, 5, 1, 13, 27, 20, 7, 1, 34, 80, 73, 35, 9, 1, 89, 234, 252, 151, 54, 11, 1, 233, 677, 837, 597, 269, 77, 13, 1, 610, 1941, 2702, 2225, 1199, 435, 104, 15, 1, 1597, 5523, 8533, 7943, 4956, 2158, 657, 135, 17, 1 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 0,4 COMMENTS Row sums are A006012. Diagonal sums are A147704. Equal to A062110*A007318 when A062110 is regarded as a triangle read by rows. LINKS Indranil Ghosh, Rows 0..100, flattened FORMULA Riordan array ((1-2x)/(1-3x+x^2), x(1-x)/(1-3x+x^2)). Sum_{k, 0<=k<=n}T(n,k)*x^k = A152239(n), A152223(n), A152185(n), A152174(n), A152167(n), A152166(n), A152163(n), A000007(n), A001519(n), A006012(n), A081704(n), A082761(n), A147837(n), A147838(n), A147839(n), A147840(n), A147841(n), for x = -8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8 respectively . - Philippe Deléham, Dec 01 2008 G.f.: (1-2*x)/(1-(3+y)*x+(1+y)*x^2). - Philippe Deléham, Nov 26 2011 T(n,k) = 3*T(n-1,k) + T(n-1,k-1) - T(n-2,k) - T(n-2,k-1), for n>1. - Philippe Deléham, Feb 12 2012 EXAMPLE Triangle begins 1, 1, 1, 2, 3, 1, 5, 9, 5, 1, 13, 27, 20, 7, 1, 34, 80, 73, 35, 9, 1, 89, 234, 252, 151, 54, 11, 1 MATHEMATICA nmax=9; Flatten[CoefficientList[Series[CoefficientList[Series[(1 - 2*x)/(1 - (3 + y)*x + (1 + y)*x^2), {x, 0, nmax}], x], {y, 0, nmax}], y]] (* Indranil Ghosh, Mar 11 2017 *) CROSSREFS Cf. A206800 Sequence in context: A293287 A236843 A055905 * A147747 A039599 A154380 Adjacent sequences:  A147700 A147701 A147702 * A147704 A147705 A147706 KEYWORD easy,nonn,tabl AUTHOR Paul Barry, Nov 10 2008 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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified October 20 17:39 EDT 2018. Contains 316394 sequences. (Running on oeis4.)