Abstract
Let spt(n) denote the total number of appearances of the smallest parts in all the partitions of n. In 1988, the second author gave new combinatorial interpretations of Ramanujan’s partition congruences mod 5, 7 and 11 in terms of a crank for weighted vector partitions. In 2008, the first author found Ramanujan-type congruences for the spt-function mod 5, 7 and 13. We give new combinatorial interpretations of the spt-congruences mod 5 and 7. These are in terms of the same crank but for a restricted set of vector partitions. The proof depends on relating the spt-crank with the crank of vector partitions and the Dyson rank of ordinary partitions. We derive a number of identities for spt-crank modulo 5 and 7. We prove the surprising result that all the spt-crank coefficients are nonnegative.
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The first author was supported in part by NSA Grant H9820-12-1-0205.
The second author was supported in part by NSA Grant H98230-09-1-0051.
The third author was supported by the Summer Research Experience for Rising Seniors (SRRS) program of the University of Florida with funding from the Howard Hughes Medical Institute the Science for Life Program.
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Andrews, G.E., Garvan, F.G. & Liang, J. Combinatorial interpretations of congruences for the spt-function. Ramanujan J 29, 321–338 (2012). https://doi.org/10.1007/s11139-012-9369-7
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DOI: https://doi.org/10.1007/s11139-012-9369-7
Keywords
- Spt-function
- Partitions
- Rank
- Crank
- Vector partitions
- Ramanujan’s Lost Notebook
- Congruences
- Basic hypergeometric series