cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-3 of 3 results.

A331417 Maximum sum of primes of the parts of an integer partition of n.

Original entry on oeis.org

0, 2, 4, 6, 8, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269
Offset: 0

Views

Author

Gus Wiseman, Jan 17 2020

Keywords

Comments

For n > 4, a(n) = prime(n).

Crossrefs

Converges to A000040.
Row lengths of A331416.
The corresponding minimum is A007494.
Partitions whose sum of primes is divisible by their sum are A331379.

Programs

  • Mathematica
    Table[Max@@Table[Total[Prime/@y],{y,IntegerPartitions[n]}],{n,0,10}]

Formula

a(n) = A331418(n) + n - 1.

A144419 Primes of the form prime(k) - 2*k (terms can be repeated).

Original entry on oeis.org

3, 3, 5, 13, 17, 29, 31, 31, 37, 41, 47, 53, 67, 71, 71, 79, 79, 83, 89, 97, 97, 107, 107, 127, 131, 151, 181, 197, 211, 229, 241, 257, 257, 269, 271, 281, 283, 283, 311, 353, 373, 389, 401, 409, 409, 419, 419, 431, 449, 463, 479, 491, 499, 547, 563, 577, 577
Offset: 1

Views

Author

Juri-Stepan Gerasimov, Oct 07 2008

Keywords

Examples

			For k=7,  prime(7)  - 2*7  = 17 - 14 =  3 = a(1).
For k=8,  prime(8)  - 2*8  =  9 - 16 =  3 = a(2).
For k=9,  prime(9)  - 2*9  = 23 - 18 =  5 = a(3).
For k=12, prime(12) - 2*12 = 37 - 24 = 13 = a(4).
For k=15, prime(15) - 2*15 = 47 - 30 = 17 = a(5).
For k=19, prime(19) - 2*19 = 67 - 38 = 29 = a(6).
For k=20, prime(20) - 2*20 = 71 - 40 = 31 = a(7).
		

Crossrefs

Programs

  • Maple
    select(isprime, [seq(ithprime(k)-2*k,k=1..1000)]); # Robert Israel, Nov 24 2024

Extensions

A 181 replaced with 281 by R. J. Mathar, Apr 14 2010

A173072 n-th prime minus n-th even number.

Original entry on oeis.org

2, 1, 1, 1, 3, 3, 5, 5, 7, 11, 11, 15, 17, 17, 19, 23, 27, 27, 31, 33, 33, 37, 39, 43, 49, 51, 51, 53, 53, 55, 67, 69, 73, 73, 81, 81, 85, 89, 91, 95, 99, 99, 107, 107, 109, 109, 119, 129, 131, 131, 133, 137, 137, 145, 149, 153, 157, 157, 161, 163, 163, 171, 183, 185
Offset: 1

Views

Author

Juri-Stepan Gerasimov, Feb 09 2010

Keywords

Crossrefs

See A179437 for another version.

Programs

  • Mathematica
    Table[Prime[n]-2(n-1),{n,70}] (* Harvey P. Dale, Jul 04 2016 *)

Formula

a(n)=A000040(n) - 2n + 2.

Extensions

Edited by Charles R Greathouse IV, Mar 24 2010
Showing 1-3 of 3 results.