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 A324927 Matula-Goebel numbers of rooted trees of depth 2. Numbers that are not powers of 2 but whose prime indices are all powers of 2. 5
 3, 6, 7, 9, 12, 14, 18, 19, 21, 24, 27, 28, 36, 38, 42, 48, 49, 53, 54, 56, 57, 63, 72, 76, 81, 84, 96, 98, 106, 108, 112, 114, 126, 131, 133, 144, 147, 152, 159, 162, 168, 171, 189, 192, 196, 212, 216, 224, 228, 243, 252, 262, 266, 288, 294, 304, 311, 318 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Numbers n such that A109082(n) = 2. A prime index of n is a number m such that prime(m) divides n. The multiset of prime indices of n is row n of A112798. Also Heinz numbers of integer partitions into powers of 2 with at least one part > 1 (counted by A102378). LINKS EXAMPLE The sequence of terms together with their prime indices begins:    3: {2}    6: {1,2}    7: {4}    9: {2,2}   12: {1,1,2}   14: {1,4}   18: {1,2,2}   19: {8}   21: {2,4}   24: {1,1,1,2}   27: {2,2,2}   28: {1,1,4}   36: {1,1,2,2}   38: {1,8}   42: {1,2,4}   48: {1,1,1,1,2}   49: {4,4}   53: {16}   54: {1,2,2,2}   56: {1,1,1,4} MATHEMATICA Select[Range[100], And[!IntegerQ[Log[2, #]], And@@Cases[FactorInteger[#], {p_, _}:>IntegerQ[Log[2, PrimePi[p]]]]]&] CROSSREFS Cf. A000081, A000720, A003963, A007097, A018819, A033844, A056239, A102378, A112798, A302242, A318400, A324928, A324929. Sequence in context: A176409 A284473 A120684 * A026227 A026232 A286802 Adjacent sequences:  A324924 A324925 A324926 * A324928 A324929 A324930 KEYWORD nonn AUTHOR Gus Wiseman, Mar 21 2019 STATUS approved

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Last modified May 19 09:24 EDT 2019. Contains 323390 sequences. (Running on oeis4.)