A030194 a(0)=0; a(n) is the smallest m such that m - a(i) is not a triangular number for any i < n.
0, 2, 4, 9, 11, 13, 18, 20, 22, 27, 29, 31, 51, 53, 60, 62, 69, 71, 85, 94, 101, 103, 110, 112, 141, 143, 150, 152, 159, 161, 168, 170, 211, 220, 229, 245, 267, 269, 292, 299, 301, 308, 310, 317, 319, 326, 348, 357, 359, 366, 368, 375, 418, 427, 456, 458, 499, 508
Offset: 0
Keywords
References
- A. Sárközy. On the difference sets of sequences of integers II, Ann. Univ. Sci. Budapest. Eotvos Sect. Math. 21(1978), 45-53.
Links
- Hugo Pfoertner, Table of n, a(n) for n = 0..10000
- I. Ruzsa, Difference sets without squares, Period. Math. Hungar. 15 (1984), no. 3, 205-209.
- A. Sárközy, On difference sets of sequences of integers I, Acta Mathematica Academiae Scientiarum Hungarica, March 1978, Volume 31, Issue 1, pp 125-149.
- A. Sárközy, On difference sets of sequences of integers III, Acta Mathematica Academiae Scientiarum Hungarica, September 1978, Volume 31, Issue 3, pp 355-386.
Programs
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PARI
a030194(upto)={my(a=vector(upto));a[1]=2;for(n=2,upto,for(m=a[n-1]+1,oo,my(f=1);for(j=1,n,if(ispolygonal(m-a[j],3),f=0;break));if(f,a[n]=m;break)));concat([0],a)}; a030194(57) \\ Hugo Pfoertner, Oct 05 2020
Extensions
Name edited by Michel Marcus, Oct 05 2020
More terms from Hugo Pfoertner, Oct 05 2020