OFFSET
1,11
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..1001
FORMULA
(a(n)) satisfies : a(k)=1 for 1<=k<=8 then for n>=1 a(6n+2)=a(6n+3)=a(6n+4)=a(6n+6); a(6n+5)=a(6n+7)=a(6*n+2)+A000245(n)
a(6n-1) = a(6n+1) = a(6n+2) = a(6n+3) = a(6n+4) = a(6n+6) = A000108(n) except a(-1) = 0; generating function = (1-sqrt(1-4x^6))(1+x^2+x^3+x^4+x^5+x^7)/(2x^7)-1/x. - Alec Mihailovs (alec(AT)mihailovs.com), Jun 16 2004
MAPLE
MATHEMATICA
Rest[CoefficientList[Series[(1-Sqrt[1-4x^6])(1+x^2+x^3+x^4+x^5+x^7)/ (2x^7)- 1/x, {x, 0, 70}], x]] (* Harvey P. Dale, Aug 29 2011 *)
PROG
(PARI) v=vector(90, j, 1); for(n=7, 90, A=sum(i=1, n, sum(j=1, n, if(2*i+3*j-n, 0, v[2*i]*v[3*j]))); v[n]=A); a(n)=v[n];
CROSSREFS
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Jun 14 2004
STATUS
approved