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!)
A328024 Heinz numbers of multisets representing the differences between some positive integer's consecutive divisors. 4
1, 2, 3, 6, 7, 13, 20, 29, 37, 39, 42, 53, 61, 79, 107, 110, 113, 151, 173, 181, 199, 239, 261, 271, 281, 312, 317, 349, 359, 374, 397, 421, 457, 497, 503, 541, 557, 577, 593, 613, 701, 733, 769, 787, 798, 857, 863, 903, 911, 953, 983, 1021, 1061, 1069, 1151 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
The Heinz number of an integer partition or multiset {y_1,...,y_k} is prime(y_1)*...*prime(y_k).
There is exactly one entry with any given sum of prime indices A056239.
LINKS
EXAMPLE
The sequence of terms together with their prime indices begins:
1: {}
2: {1}
3: {2}
6: {1,2}
7: {4}
13: {6}
20: {1,1,3}
29: {10}
37: {12}
39: {2,6}
42: {1,2,4}
53: {16}
61: {18}
79: {22}
107: {28}
110: {1,3,5}
113: {30}
151: {36}
173: {40}
181: {42}
199: {46}
239: {52}
261: {2,2,10}
271: {58}
281: {60}
312: {1,1,1,2,6}
For example, the divisors of 8 are {1,2,4,8}, with differences {1,2,4}, with Heinz number 42, so 42 belongs to the sequence.
MATHEMATICA
nn=1000;
Select[Union[Table[Times@@Prime/@Differences[Divisors[n]], {n, nn}]], #<=nn&]
CROSSREFS
A permutation of A328023.
Also the set of possible Heinz numbers of rows of A193829, A328025, or A328027.
Sequence in context: A328164 A294916 A233423 * A309815 A256800 A172105
KEYWORD
nonn
AUTHOR
Gus Wiseman, Oct 02 2019
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 April 25 03:15 EDT 2024. Contains 371964 sequences. (Running on oeis4.)