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A319353 Filter sequence combining weights of partitions with Heinz-numbers equal to the proper divisors of n. 4

%I #8 Sep 17 2018 15:46:02

%S 1,2,2,3,2,4,2,4,5,6,2,7,2,8,9,10,2,11,2,11,12,13,2,14,15,16,12,17,2,

%T 18,2,11,19,20,21,22,2,23,24,18,2,25,2,26,27,28,2,29,30,31,32,33,2,25,

%U 34,25,35,36,2,37,2,38,39,40,41,42,2,43,44,45,2,37,2,46,47,48,49,50,2,51,52,53,2,54,55,56,57,42,2,58,59,60,61,62,63,37,2,64,65

%N Filter sequence combining weights of partitions with Heinz-numbers equal to the proper divisors of n.

%C Restricted growth sequence transform of A319352.

%C For all i, j:

%C a(i) = a(j) => A301855(i) = A301855(j).

%C a(i) = a(j) => A304793(i) = A304793(j).

%H Antti Karttunen, <a href="/A319353/b319353.txt">Table of n, a(n) for n = 1..65537</a>

%o (PARI)

%o up_to = 65537;

%o rgs_transform(invec) = { my(om = Map(), outvec = vector(length(invec)), u=1); for(i=1, length(invec), if(mapisdefined(om,invec[i]), my(pp = mapget(om, invec[i])); outvec[i] = outvec[pp] , mapput(om,invec[i],i); outvec[i] = u; u++ )); outvec; };

%o A056239(n) = { my(f); if(1==n, 0, f=factor(n); sum(i=1, #f~, f[i,2] * primepi(f[i,1]))); }

%o A319352(n) = { my(m=1); fordiv(n, d, if(d<n, m *= prime(1+A056239(d)))); (m); };

%o v319353 = rgs_transform(vector(up_to,n,A319352(n)));

%o A319353(n) = v319353[n];

%Y Cf. A056239, A319352.

%K nonn

%O 1,2

%A _Antti Karttunen_, Sep 17 2018

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Last modified August 27 12:59 EDT 2024. Contains 375469 sequences. (Running on oeis4.)