The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A301957 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A301957

Number of distinct subset-products of the integer partition with Heinz number n.
(history; published version)

#16 by Susanna Cuyler at Fri Sep 07 04:42:26 EDT 2018

STATUS

proposed

approved

#15 by Antti Karttunen at Thu Sep 06 07:56:34 EDT 2018

STATUS

editing

proposed

#14 by Antti Karttunen at Thu Sep 06 07:56:30 EDT 2018

LINKS

<a href="/index/Pri#prime_indices">Index entries for sequences computed from indices in prime factorization</a>

STATUS

reviewed

editing

#13 by Peter Luschny at Wed Sep 05 14:58:57 EDT 2018

STATUS

proposed

reviewed

#12 by Peter Luschny at Wed Sep 05 14:58:44 EDT 2018

STATUS

editing

proposed

#11 by Peter Luschny at Wed Sep 05 14:58:19 EDT 2018

COMMENTS

Number of distinct values obtained when A003963 is applied to all dividors divisors of n. - Antti Karttunen, Sep 05 2018

STATUS

proposed

editing

#10 by Antti Karttunen at Wed Sep 05 14:45:03 EDT 2018

STATUS

editing

proposed

#9 by Antti Karttunen at Wed Sep 05 14:43:07 EDT 2018

LINKS

Antti Karttunen, <a href="/A301957/b301957.txt">Table of n, a(n) for n = 1..65537</a>

#8 by Antti Karttunen at Wed Sep 05 14:40:45 EDT 2018

DATA

1, 1, 2, 1, 2, 2, 2, 1, 3, 2, 2, 2, 2, 2, 4, 1, 2, 3, 2, 2, 4, 2, 2, 2, 3, 2, 4, 2, 2, 4, 2, 1, 4, 2, 4, 3, 2, 2, 4, 2, 2, 4, 2, 2, 6, 2, 2, 2, 3, 3, 4, 2, 2, 4, 4, 2, 4, 2, 2, 4, 2, 2, 5, 1, 4, 4, 2, 2, 4, 4, 2, 3, 2, 2, 6, 2, 4, 4, 2, 2, 5, 2, 2, 4, 4, 2, 4, 2, 2, 6, 4, 2, 4, 2, 4, 2, 2, 3, 6, 3, 2, 4, 2, 2, 8

COMMENTS

Number of distinct values obtained when A003963 is applied to all dividors of n. - Antti Karttunen, Sep 05 2018

PROG

(PARI)

up_to = 65537;

A003963(n) = { n=factor(n); n[, 1]=apply(primepi, n[, 1]); factorback(n) }; \\ From A003963

v003963 = vector(up_to, n, A003963(n));

A301957(n) = { my(m=Map(), s, k=0, c); fordiv(n, d, if(!mapisdefined(m, s = v003963[d], &c), mapput(m, s, s); k++)); (k); }; \\ Antti Karttunen, Sep 05 2018

CROSSREFS

Cf. A000712, A001055, A001227, A002865, A003963, A108917, A162247, A276024, A292886, A301854, A301855, A301856, A301970, A301979, A304793.

EXTENSIONS

More terms from Antti Karttunen, Sep 05 2018

STATUS

approved

editing

#7 by Susanna Cuyler at Sun Apr 08 20:10:14 EDT 2018

STATUS

proposed

approved