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.

A082246 Primes that are the sum of 7 consecutive primes.

Original entry on oeis.org

197, 223, 251, 281, 311, 401, 431, 463, 523, 593, 659, 719, 757, 827, 863, 947, 991, 1063, 1171, 1753, 1901, 2347, 2393, 2647, 2689, 2731, 2777, 2819, 2953, 3347, 3389, 3533, 3643, 3701, 3761, 3821, 4177, 4217, 4451, 4493, 5507, 5717, 5849, 5927, 6029
Offset: 1

Views

Author

Cino Hilliard, May 09 2003

Keywords

Examples

			2 + 3 + 5 + 7 + 11 + 13 + 17 = 58 = 2*29
3 + 5 + 7 + 11 + 13 + 17 + 19 = 75 = 3*5^2
5 + 7 + 11 + 13 + 17 + 19 + 23 = 95 = 5*19
7 + 11 + 13 + 17 + 19 + 23 + 29 = 119 = 7*17
11 + 13 + 17 + 19 + 23 + 29 + 31 = 143 = 11*13
13 + 17 + 19 + 23 + 29 + 31 + 37 = 169 = 13*13
17 + 19 + 23 + 29 + 31 + 37 + 41 = 197 (prime)
		

Crossrefs

Cf. A180948.

Programs

  • Maple
    Primes:= select(isprime, [seq(i,i=3..10000,2)]):
    S:= ListTools:-PartialSums(Primes):
    select(isprime,S[8..-1]-S[1..-8]); # Robert Israel, Dec 14 2017
  • Mathematica
    Select[ListConvolve[{1,1,1,1,1,1,1},Prime[Range[200]]],PrimeQ] (* Harvey P. Dale, Jul 12 2013 *)
    Select[Total/@Partition[Prime[Range[200]],7,1],PrimeQ] (* Harvey P. Dale, Jul 24 2017 *)
  • PARI
    \\ primes in the sum of m odd number of consecutive primes. m=7
    psumprm(m,n) = { sr=0; s=0; for(j=1,m, s+=prime(j); ); for(x=1,n, s = s - prime(x)+ prime(x+m); if(isprime(s),sr+=1.0/s; print1(s" ")); ); print(); print(sr) }

Extensions

Corrected by Michael Somos, Feb 01 2004