login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A053692 Number of self-conjugate 4-core partitions of n. 6
1, 1, 0, 1, 1, 1, 1, 1, 0, 0, 2, 0, 1, 1, 1, 2, 0, 0, 1, 1, 0, 1, 1, 0, 1, 2, 0, 2, 1, 0, 1, 0, 1, 1, 1, 0, 1, 0, 0, 1, 3, 1, 0, 1, 0, 2, 1, 0, 1, 1, 1, 0, 1, 0, 0, 2, 0, 1, 0, 1, 2, 2, 0, 1, 0, 0, 2, 1, 1, 1, 2, 0, 0, 0, 0, 1, 1, 0, 2, 1, 0, 1, 1, 0, 1, 2, 0, 1, 1, 0, 3, 1, 0, 0, 1, 2, 1, 0, 0, 1, 0, 0, 1, 1, 0 (list; graph; refs; listen; history; internal format)
OFFSET

0,11

COMMENTS

Ramanujan theta functions: f(q) := Prod_{k>=1} (1-(-q)^k) (see A121373), phi(q) := theta_3(q) := Sum_{k=-oo..oo} q^(k^2) (A000122), psi(q) := Sum_{k=0..oo} q^(k*(k+1)/2) (A10054), chi(q) := Prod_{k>=0} (1+q^(2k+1)) (A000700).

Euler transform of period 8 sequence [1,-1,1,0,1,-1,1,-2,...].

Expansion of q^(-5/8)eta(q^2)^2eta(q^8)^2/(eta(q)eta(q^4)) in powers of q.

REFERENCES

B. C. Berndt, Ramanujan's Notebooks Part IV, Springer-Verlag, see p. 153 Entry 22.

Garvan, F., Kim, D. and Stanton, D., Cranks and t-cores, Inventiones Math. 101 (1990) 1-17

LINKS

M. Somos, Introduction to Ramanujan theta functions

Eric Weisstein's World of Mathematics, Ramanujan Theta Functions

FORMULA

G.f.: product((1-q^(8*i))^2*(1-q^(4*i-2))/(1-q^(2*i-1)), i=1..inifinity)

G.f.: psi(x)psi(x^4) where psi(x) is a Ramanujan theta function. - Michael Somos Nov 03 2005

G.f.: Sum_{k} x^k/(1-x^(8k+5)). - Michael Somos Nov 03 2005

PROG

(PARI) {a(n)=local(A); if(n<0, 0, A=sum(k=0, ceil(sqrtint(8*n+1)/2), x^((k^2+k)/2), x*O(x^n)); polcoeff( A*subst(A+x*O(x^(n\4)), x, x^4), n))} /* Michael Somos Nov 03 2005 */

(PARI) {a(n)=local(A); if(n<0, 0, A=x*O(x^n); polcoeff( eta(x^2+A)^2*eta(x^8+A)^2/ eta(x+A)/eta(x^4+A), n))}

CROSSREFS

Cf. A053693.

Sequence in context: A050332 A029425 A025902 * A099494 A030341 A121444

Adjacent sequences:  A053689 A053690 A053691 * A053693 A053694 A053695

KEYWORD

easy,nonn

AUTHOR

James A. Sellers (sellersj(AT)math.psu.edu), Feb 14 2000

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 14 20:13 EST 2012. Contains 205663 sequences.