login
A029007
Expansion of 1/((1-x)(1-x^2)(1-x^4)(1-x^5)).
2
1, 1, 2, 2, 4, 5, 7, 8, 11, 13, 17, 19, 24, 27, 33, 37, 44, 49, 57, 63, 73, 80, 91, 99, 112, 122, 136, 147, 163, 176, 194, 208, 228, 244, 266, 284, 308, 328, 354, 376, 405, 429, 460, 486, 520, 549, 585, 616, 655, 689
OFFSET
0,3
COMMENTS
Partitions of n into parts 1, 2, 4 and 5. - David Neil McGrath, Sep 14 2014
LINKS
Xiangyu Ding and Lisa Hui Sun, Truncated theta series from the Bailey lattice, arXiv:2403.11608 [math.CO], 2024. See p. 18.
Index entries for linear recurrences with constant coefficients, signature (1,1,-1,1,0,-2,0,1,-1,1,1,-1).
FORMULA
a(0)=1, a(1)=1, a(2)=2, a(3)=2, a(4)=4, a(5)=5, a(6)=7, a(7)=8, a(8)=11, a(9)=13, a(10)=17, a(11)=19, a(n)=a(n-1)+a(n-2)-a(n-3)+a(n-4)- 2*a(n-6)+ a(n-8)-a(n-9)+a(n-10)+a(n-11)-a(n-12). - Harvey P. Dale, Dec 06 2013
a(n) = floor((2*n^3+36*n^2+193*n+525)/480+(n+1)*(-1)^n/32). - Tani Akinari, Sep 30 2014
Euler transform of length 5 sequence [ 1, 1, 0, 1, 1]. - Michael Somos, Sep 30 2014
a(n) = -a(-12-n) for all n in Z. - Michael Somos, Sep 30 2014
0 = a(n) - a(n+1) - a(n+5) + a(n+6) for all odd n in Z. - Michael Somos, Sep 30 2014
0 = a(n) - a(n+1) - a(n+5) + a(n+6) - floor((n+10)/4) for all even n in Z. - Michael Somos, Sep 30 2014
EXAMPLE
There are 7 partitions of 6 from 1,2,4 and 5. These are (51)(42)(411)(222)(2211)(21111)(111111). - David Neil McGrath, Sep 14 2014
G.f. = 1 + x + 2*x^2 + 2*x^3 + 4*x^4 + 5*x^5 + 7*x^6 + 8*x^7 + 11*x^8 + ...
MAPLE
f:= gfun[rectoproc]({a(0)=1, a(1)=1, a(2)=2, a(3)=2, a(4)=4, a(5)=5, a(6)=7, a(7)=8, a(8)=11, a(9)=13, a(10)=17, a(11)=19, a(n)=a(n-1)+a(n-2)-a(n-3)+a(n-4)- 2*a(n-6)+ a(n-8)-a(n-9)+a(n-10)+a(n-11)-a(n-12)}, a(n)):
seq(f(n), n=0..100); # Robert Israel, Sep 14 2014
MATHEMATICA
CoefficientList[Series[1/((1-x)(1-x^2)(1-x^4)(1-x^5)), {x, 0, 50}], x] (* or *) LinearRecurrence[{1, 1, -1, 1, 0, -2, 0, 1, -1, 1, 1, -1}, {1, 1, 2, 2, 4, 5, 7, 8, 11, 13, 17, 19}, 50] (* Harvey P. Dale, Dec 06 2013 *)
PROG
(PARI) a(n)=my(v=apply(u->for(i=1, #u, if(u[i]==3, return(0))); 1, partitions(n, 5))); sum(i=1, #v, v[i]) \\ Charles R Greathouse IV, Sep 15 2014
CROSSREFS
Sequence in context: A067957 A120326 A036406 * A338202 A348552 A058678
KEYWORD
nonn,easy
AUTHOR
STATUS
approved