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A340386 Heinz numbers of integer partitions with an odd number of parts, the greatest of which is odd.

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%I A340386 #8 Jan 25 2021 19:04:13
%S A340386 2,5,8,11,17,20,23,30,31,32,41,44,45,47,50,59,66,67,68,73,75,80,83,92,
%T A340386 97,99,102,103,109,110,120,124,125,127,128,137,138,149,153,154,157,
%U A340386 164,165,167,170,176,179,180,186,188,191,197,200,207,211,227,230
%N A340386 Heinz numbers of integer partitions with an odd number of parts, the greatest of which is odd.
%C A340386 The Heinz number of a partition (y_1,...,y_k) is prime(y_1)*...*prime(y_k). This gives a bijective correspondence between positive integers and integer partitions.
%F A340386 Intersection of A026424 (odd length) and A244991 (odd maximum).
%e A340386 The sequence of partitions together with their Heinz numbers begins:
%e A340386       2: (1)             59: (17)           120: (3,2,1,1,1)
%e A340386       5: (3)             66: (5,2,1)        124: (11,1,1)
%e A340386       8: (1,1,1)         67: (19)           125: (3,3,3)
%e A340386      11: (5)             68: (7,1,1)        127: (31)
%e A340386      17: (7)             73: (21)           128: (1,1,1,1,1,1,1)
%e A340386      20: (3,1,1)         75: (3,3,2)        137: (33)
%e A340386      23: (9)             80: (3,1,1,1,1)    138: (9,2,1)
%e A340386      30: (3,2,1)         83: (23)           149: (35)
%e A340386      31: (11)            92: (9,1,1)        153: (7,2,2)
%e A340386      32: (1,1,1,1,1)     97: (25)           154: (5,4,1)
%e A340386      41: (13)            99: (5,2,2)        157: (37)
%e A340386      44: (5,1,1)        102: (7,2,1)        164: (13,1,1)
%e A340386      45: (3,2,2)        103: (27)           165: (5,3,2)
%e A340386      47: (15)           109: (29)           167: (39)
%e A340386      50: (3,3,1)        110: (5,3,1)        170: (7,3,1)
%t A340386 Select[Range[100],OddQ[PrimeOmega[#]*PrimePi[FactorInteger[#][[-1,1]]]]&]
%Y A340386 Note: Heinz numbers are given in parentheses below.
%Y A340386 The case of odd length only is A026424.
%Y A340386 The case of odd maximum only is A244991.
%Y A340386 Positions of odd terms in A326846.
%Y A340386 These partitions are counted by A340385.
%Y A340386 The version for factorizations is A340607.
%Y A340386 A000009 counts partitions into odd parts (A066208).
%Y A340386 A027193 counts partitions of odd length, or of odd maximum.
%Y A340386 A061395 gives maximum prime index.
%Y A340386 A106529 lists numbers with Omega equal to maximum prime index.
%Y A340386 A160786 counts odd-length partitions of odd numbers (A300272).
%Y A340386 A339890 counts factorizations of odd length.
%Y A340386 A340102 counts odd-length factorizations into odd factors.
%Y A340386 Cf. A001222, A027187, A056239, A112798, A236914, A258116, A300063, A324522, A340608, A340788, A340831.
%K A340386 nonn
%O A340386 1,1
%A A340386 _Gus Wiseman_, Jan 25 2021