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A123929
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Simili-primes of order 2.
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10
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3, 5, 8, 13, 17, 22, 28, 31, 38, 43, 47, 53, 59, 67, 73, 77, 82, 89, 97, 101, 107, 113, 121, 127, 133, 139, 148, 151, 158, 163, 167, 179, 191, 197, 203, 209, 218, 227, 233, 241, 251, 257, 262, 269, 274, 281, 284, 293, 307, 313, 317, 322, 332, 343, 347, 353, 361
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OFFSET
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1,1
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COMMENTS
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Start examining the natural numbers from 2 on and call an "atom" the first integer which cannot be divided by another "atom"; this sieve produces the prime numbers. Here we call "atom" the second integer which cannot be divided by another "atom" - thus the sequence starts with 3 (not 2) and continues with 5 (not 4), then 8 (not 6 or 7), then 13, etc.
Terms computed by Mensanator.
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REFERENCES
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J.-P. Delahaye, La suite du lézard et autres inventions, Pour la Science, No. 353, 2007.
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LINKS
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FORMULA
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Conjecture : a(n) is asymptotic to c*n*log(n) with c about 1.5. - Benoit Cloitre, Feb 11 2007
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PROG
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(PARI) A123929(n, mode=0/*+1=print, +2=return list*/, N=2, P=List(N+1))={ while(n--, my(k=P[#P]); for(i=1, N, while(k++, for(j=1, #P, k%P[j]||next(2)); break)); bittest(mode, 0)&&print1(k", "); listput(P, k)); if(bittest(mode, 1), Vec(P), P[#P])} \\ M. F. Hasler, Dec 24 2013
(PARI) v=vectorsmall(10^3); u=List(); v[n=1]=1; while(n<#v*99/100, while(v[n++], ); while(v[n++], ); listput(u, n); forstep(k=2*n, #v, n, v[k]=1)); Vec(u) \\ Charles R Greathouse IV, Jan 02 2014
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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STATUS
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approved
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