login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A319353 Filter sequence combining weights of partitions with Heinz-numbers equal to the proper divisors of n. 4
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, 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, 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 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Restricted growth sequence transform of A319352.
For all i, j:
a(i) = a(j) => A301855(i) = A301855(j).
a(i) = a(j) => A304793(i) = A304793(j).
LINKS
PROG
(PARI)
up_to = 65537;
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; };
A056239(n) = { my(f); if(1==n, 0, f=factor(n); sum(i=1, #f~, f[i, 2] * primepi(f[i, 1]))); }
A319352(n) = { my(m=1); fordiv(n, d, if(d<n, m *= prime(1+A056239(d)))); (m); };
v319353 = rgs_transform(vector(up_to, n, A319352(n)));
A319353(n) = v319353[n];
CROSSREFS
Sequence in context: A297169 A353565 A318835 * A319343 A300827 A144371
KEYWORD
nonn
AUTHOR
Antti Karttunen, Sep 17 2018
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 28 09:04 EDT 2024. Contains 371240 sequences. (Running on oeis4.)