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.

A097505 Triangle read by rows: T(n,k) = Sum_{j=1..k} Prime(n+j-1).

Original entry on oeis.org

2, 3, 8, 5, 12, 23, 7, 18, 31, 48, 11, 24, 41, 60, 83, 13, 30, 49, 72, 101, 132, 17, 36, 59, 88, 119, 156, 197, 19, 42, 71, 102, 139, 180, 223, 270, 23, 52, 83, 120, 161, 204, 251, 304, 363, 29, 60, 97, 138, 181, 228, 281, 340, 401, 468, 31, 68, 109, 152, 199, 252, 311, 372, 439, 510, 583
Offset: 1

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Author

Reinhard Zumkeller, Aug 26 2004

Keywords

Programs

  • Magma
    [&+[NthPrime(n+j-1): j in [1..k]] : k in [1..n], n in [1..12]]; // G. C. Greubel, Jan 19 2020
    
  • Maple
    seq(seq( sum(ithprime(n+j-1), j=1..k), k=1..n), n=1..12); # G. C. Greubel, Jan 19 2020
  • Mathematica
    Table[Sum[Prime[n+j-1], {j,k}], {n,12}, {k,n}]//Flatten (* G. C. Greubel, Jan 19 2020 *)
  • PARI
    T(n,k) = sum(j=1,k, prime(n+j-1)); \\ G. C. Greubel, Jan 19 2020
    
  • Sage
    [[sum(nth_prime(n+j-1) for j in (1..k)) for k in (1..n)] for n in (1..12)] # G. C. Greubel, Jan 19 2020

Formula

T(n,k) = A007504(n+k) - A007504(n-1).
T(n,0) = A000040(n).
T(n,1) = A001043(n) for n>1.
T(n,2) = A034961(n) for n>1.