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Heinz numbers of integer partitions whose length is equal to their LCM.
11

%I #17 Jul 05 2018 14:21:56

%S 2,6,9,20,50,56,84,125,126,176,189,196,240,294,360,416,441,540,600,

%T 624,686,810,900,936,968,1029,1040,1088,1215,1350,1404,1500,1560,2025,

%U 2106,2250,2340,2401,2432,2600,2704,3159,3375,3510,3648,3750,3900,4056,5265

%N Heinz numbers of integer partitions whose length is equal to their LCM.

%C A110295 is a subsequence.

%H David A. Corneth, <a href="/A316429/b316429.txt">Table of n, a(n) for n = 1..10822</a> (Terms <= 5 * 10^11)

%e 3750 is the Heinz number of (3,3,3,3,2,1), whose length and lcm are both 6.

%t Select[Range[2,200],PrimeOmega[#]==LCM@@Cases[FactorInteger[#],{p_,k_}:>PrimePi[p]]&]

%o (PARI) heinz(n) = my(f=factor(n), pr=f[,1]~,exps=f[,2], res=vector(vecsum(exps)), t=0); for(i = 1, #pr, pr[i] = primepi(pr[i]); for(j=1, exps[i],t++; res[t] = pr[i])); res

%o is(n) = my(h = heinz(n)); lcm(h)==#h \\ _David A. Corneth_, Jul 05 2018

%Y Cf. A056239, A074761, A110295, A143773, A237984, A289508, A289509, A290103, A296150, A316413, A316428, A316430, A316431.

%K nonn,easy

%O 1,1

%A _Gus Wiseman_, Jul 02 2018