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.
Accumulate[2^MersennePrimeExponent[Range[15]]-1] (* Harvey P. Dale, Feb 28 2023 *)
Accumulate[(# (#+1))/2&/@Select[2^Range[90]-1,PrimeQ] ]/2 (* Harvey P. Dale, Sep 04 2014 *)
1; 1, 1; 1, -16, 1; 1, -462, -462, 1; 1, -7626, -8072, -7626, 1; 1, -33542202, -33549812, -33549812, -33542202, 1; 1, -8556318714, -8589860900, -8589868064, -8589860900, -8556318714, 1; 1, -128848822266, -137405140964, -137438682704, -137438682704, -137405140964, -128848822266, 1; 1, -2305842870701260794, -2305842999550083044, -2305843008106401296, -2305843008139935872, -2305843008106401296, -2305842999550083044, -2305842870701260794, 1;
a={1,6,28,496,8128,33550336, 8589869056,137438691328,2305843008139952128,
2658455991569831744654692615953842176, 191561942608236107294793378084303638130997321548169216}
t[n_,m_]:=(-a[[n+1]]+(a[[m+1]]+a[[n-m+1]]));
Table[Table[t[n,m],{m,0,n}],{n,0,10}];
Flatten[%]
Comments