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.

A376681 Row sums of the absolute value of the array A095195(n, k) = n-th term of the k-th differences of the prime numbers (A000040).

Original entry on oeis.org

2, 4, 8, 10, 22, 36, 72, 134, 266, 500, 874, 1418, 2044, 2736, 4626, 15176, 41460, 95286, 196368, 372808, 660134, 1092790, 1682198, 2384724, 3147706, 4526812, 11037090, 36046768, 93563398, 214796426, 452129242, 885186658, 1619323680, 2763448574, 4368014812
Offset: 1

Views

Author

Gus Wiseman, Oct 15 2024

Keywords

Examples

			The fourth row of A095195 is: (7, 2, 0, -1), so a(4) = 10.
		

Crossrefs

For firsts instead of row-sums we have A007442 (modern version of A030016).
This is the absolute version of A140119.
If 1 is considered prime (A008578) we get A376684, absolute version of A376683.
For first zero-positions we have A376678 (modern version of A376855).
For composite instead of prime we have A377035.
For squarefree instead of prime we have A377040, nonsquarefree A377048.
A000040 lists the modern primes, differences A001223, seconds A036263.
A008578 lists the noncomposites, differences A075526, seconds A036263 with 0 prepended.

Programs

  • Mathematica
    nn=15;
    t=Table[Take[Differences[NestList[NestWhile[#+1&, #+1,!PrimeQ[#]&]&,2,2*nn],k],nn],{k,0,nn}]
    Total/@Abs/@Table[t[[j,i-j+1]],{i,nn},{j,i}]

Extensions

More terms from Pontus von Brömssen, Oct 17 2024