[go: up one dir, main page]

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!)
Revision History for A316413 (Underlined text is an addition; strikethrough text is a deletion.)

Showing entries 1-10 | older changes
A316413 Heinz numbers of integer partitions whose length divides their sum.
(history; published version)
#17 by Alois P. Heinz at Fri Nov 19 18:54:21 EST 2021
STATUS

editing

approved

#16 by Alois P. Heinz at Fri Nov 19 18:54:18 EST 2021
MAPLE

# second Maple program:

q:= n-> (l-> nops(l)>0 and irem(add(i, i=l), nops(l))=0)(map

(i-> numtheory[pi](i[1])$i[2], ifactors(n)[2])):

select(q, [$1..110])[]; # Alois P. Heinz, Nov 19 2021

STATUS

approved

editing

#15 by R. J. Mathar at Fri Aug 09 12:27:03 EDT 2019
STATUS

editing

approved

#14 by R. J. Mathar at Fri Aug 09 12:26:56 EDT 2019
LINKS

R. J. Mathar, <a href="/A316413/b316413.txt">Table of n, a(n) for n = 1..1327</a>

MAPLE

isA326413 := proc(n)

psigsu := A056239(n) ;

psigle := numtheory[bigomega](n) ;

if modp(psigsu, psigle) = 0 then

true;

else

false;

end if;

end proc:

n := 1:

for i from 2 to 3000 do

if isA326413(i) then

printf("%d %d\n", n, i);

n := n+1 ;

end if;

end do: # R. J. Mathar, Aug 09 2019

STATUS

approved

editing

#13 by N. J. A. Sloane at Mon Jul 02 22:39:29 EDT 2018
STATUS

proposed

approved

#12 by Gus Wiseman at Mon Jul 02 21:35:24 EDT 2018
STATUS

editing

proposed

#11 by Gus Wiseman at Mon Jul 02 12:23:29 EDT 2018
CROSSREFS

Cf. A056239, A067538, A074761, A143773, A237984, A289508, A289509, A290103, A296150, A298423, A316428, A316431.

#10 by Gus Wiseman at Mon Jul 02 11:10:21 EDT 2018
NAME

allocatedHeinz numbers of integer partitions whose length fordivides Gustheir Wisemansum.

DATA

2, 3, 4, 5, 7, 8, 9, 10, 11, 13, 16, 17, 19, 21, 22, 23, 25, 27, 28, 29, 30, 31, 32, 34, 37, 39, 41, 43, 46, 47, 49, 53, 55, 57, 59, 61, 62, 64, 67, 68, 71, 73, 78, 79, 81, 82, 83, 84, 85, 87, 88, 89, 90, 91, 94, 97, 98, 99, 100, 101, 103, 105, 107, 109, 110

OFFSET

1,1

COMMENTS

In other words, partitions whose average is an integer.

The Heinz number of an integer partition (y_1,...,y_k) is prime(y_1)*...*prime(y_k).

EXAMPLE

Sequence of partitions whose length divides their sum begins (1), (2), (11), (3), (4), (111), (22), (31), (5), (6), (1111), (7), (8), (42), (51), (9), (33), (222), (411).

MATHEMATICA

Select[Range[2, 100], Divisible[Total[Cases[FactorInteger[#], {p_, k_}:>k*PrimePi[p]]], PrimeOmega[#]]&]

CROSSREFS

Cf. A056239, A067538, A074761, A143773, A237984, A289509, A296150, A298423.

KEYWORD

allocated

nonn

AUTHOR

Gus Wiseman, Jul 02 2018

STATUS

approved

editing

#9 by Gus Wiseman at Mon Jul 02 11:10:21 EDT 2018
NAME

allocated for Gus Wiseman

KEYWORD

recycled

allocated

#8 by N. J. A. Sloane at Mon Jul 02 06:56:22 EDT 2018
STATUS

proposed

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 August 29 09:12 EDT 2024. Contains 375511 sequences. (Running on oeis4.)