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!)
A294114 Sum of the larger parts of the partitions of 2n into two parts with smaller part prime. 2

%I #17 Apr 28 2020 00:45:31

%S 0,2,7,11,20,26,39,47,55,63,82,92,115,127,139,151,180,194,227,243,259,

%T 275,314,332,350,368,386,404,451,471,522,544,566,588,610,632,691,715,

%U 739,763,828,854,923,951,979,1007,1082,1112,1142,1172,1202,1232,1315

%N Sum of the larger parts of the partitions of 2n into two parts with smaller part prime.

%H Harvey P. Dale, <a href="/A294114/b294114.txt">Table of n, a(n) for n = 1..1000</a>

%H <a href="/index/Par#part">Index entries for sequences related to partitions</a>

%F a(n) = Sum_{i=1..n} (2*n - i) * c(i), where c is the prime characteristic (A010051).

%t Table[Sum[(2 n - i) (PrimePi[i] - PrimePi[i - 1]), {i, n}], {n, 80}]

%t Table[Total[Select[IntegerPartitions[2 n,{2}],PrimeQ[#[[2]]]&][[All,1]]],{n,60}] (* _Harvey P. Dale_, Apr 19 2020 *)

%Y Cf. A010051, A294113.

%K nonn,easy

%O 1,2

%A _Wesley Ivan Hurt_, Oct 22 2017

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 20:05 EDT 2024. Contains 371254 sequences. (Running on oeis4.)