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.

A289108 Triangle read by rows: T(n,k) = (k + 1)*prime(n) + k for n > 0, 0 <= k <= n, and with T(0,0) = 1.

Original entry on oeis.org

1, 2, 5, 3, 7, 11, 5, 11, 17, 23, 7, 15, 23, 31, 39, 11, 23, 35, 47, 59, 71, 13, 27, 41, 55, 69, 83, 97, 17, 35, 53, 71, 89, 107, 125, 143, 19, 39, 59, 79, 99, 119, 139, 159, 179, 23, 47, 71, 95, 119, 143, 167, 191, 215, 239, 29, 59, 89, 119, 149, 179, 209, 239, 269, 299, 329
Offset: 0

Views

Author

Vincenzo Librandi, Sep 02 2017

Keywords

Examples

			Triangle begins:
   1;
   2,   5;
   3,   7,  11;
   5,  11,  17,  23;
   7,  15,  23,  31,  39;
  11,  23,  35,  47,  59,  71;
  13,  27,  41,  55,  69,  83,  97;
  17,  35,  53,  71,  89, 107, 125, 143;
  19,  39,  59,  79,  99, 119, 139, 159, 179;
  23,  47,  71,  95, 119, 143, 167, 191, 215, 239;
  ...
		

Crossrefs

Programs

  • Magma
    /* As triangle (here NthPrime(0)=1) */ [[(k+1)*NthPrime(n)+k: k in [0..n]]: n in [0.. 15]];
    
  • Mathematica
    Join[{1}, T[n_,k_] := (k + 1) Prime[n] + k; Table[T[n, k], {n, 10}, {k, 0, n}]//Flatten]
  • SageMath
    def A289108(n,k): return 1 if n==0 else (k+1)*nth_prime(n) +k
    flatten([[A289108(n,k) for k in range(n+1)] for n in range(13)]) # G. C. Greubel, Aug 04 2024

Extensions

Definition corrected by Bruno Berselli, Sep 06 2017