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A299099
Number of (n + 1, n + 2)-core partitions with odd parts and corresponding order ideals confined to the two outermost diagonals of P_{n + 1, n + 2}.
1
1, 2, 4, 7, 15, 27, 56, 104, 210, 398, 791, 1517, 2988, 5769, 11306, 21911, 42820, 83160, 162261, 315496, 615050, 1196676, 2331733, 4538426, 8840719, 17210905, 33521153, 65265737, 127105093, 247489812, 481963369
OFFSET
0,2
FORMULA
G.f.: -(x^4-x^3-x^2+x+1)/(x^5-x^4-2*x^3+3*x^2+x-1).
MATHEMATICA
LinearRecurrence[{1, 3, -2, -1, 1}, {1, 2, 4, 7, 15}, 40] (* Jean-François Alcover, Feb 20 2018 *)
CROSSREFS
Cf. A299102.
Sequence in context: A264292 A259592 A291220 * A248574 A136336 A244456
KEYWORD
nonn,easy
AUTHOR
Anthony Zaleski, Feb 15 2018
STATUS
approved