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.

A165286 Primes which are the sum of two or more consecutive terms of A072055.

Original entry on oeis.org

23, 61, 83, 101, 139, 157, 197, 263, 283, 293, 331, 349, 367, 383, 401, 449, 491, 509, 541, 569, 571, 577, 641, 659, 661, 701, 751, 773, 809, 811, 853, 859, 881, 887, 967, 977, 997, 1009, 1039, 1069, 1117, 1123, 1181, 1193, 1217, 1237, 1279, 1283, 1361
Offset: 1

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Comments

The terms in A072055 are odd, so the count of terms in the sum must be odd to yield a prime.

Examples

			a(1)= 5+7+11 = sum_{i=1..3} A072055(i) = 23.
a(2) = sum_{i=1..5} A072055(i) = 5+7+11+15+23 = 61. a(3) = 7+11+15+23+27 = 83.
		

Crossrefs

Programs

  • Mathematica
    lst={};Do[s=2*Prime[m]+1;Do[p=Prime[n];s+=(2*p+1);If[PrimeQ[s], If[s<=6949, AppendTo[lst,s]]],{n,m+1,6!}],{m,1,6!}];lst=Take[Union@lst,200]
    Module[{nn=100,terms},terms=2*Prime[Range[nn]]+1;Take[Union[Select[ Flatten[ Table[Total/@Partition[terms,n,1],{n,3,nn,2}]],PrimeQ]],nn/2]] (* Harvey P. Dale, Jun 11 2015 *)

Extensions

Redefined in terms of A072055; cross-references to unrelated sequences deleted - R. J. Mathar, Sep 16 2009