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 A163963 First differences of A080735. 13
 1, 2, 1, 5, 1, 11, 1, 23, 1, 47, 1, 1, 1, 97, 1, 1, 1, 197, 1, 1, 1, 397, 1, 1, 1, 797, 1, 1, 1, 1597, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3203, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 6421, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 12853, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 25717, 1, 1, 1, 51437, 1, 1, 1 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Ignoring the 1 terms we obtain A055496. If we consider sequences A_i={a_i(n)}, i=1,2,... with the same constructions as A080735, but with initials a_1(1)=2, a_2(1)=3, a_3(1)=13,..., a_m(1)=A080359(m),..., then the union of A_1,A_2,... contains all primes. LINKS G. C. Greubel, Table of n, a(n) for n = 1..5000 MAPLE A080735 := proc(n) option remember; local p ; if n = 1 then 1; else p := procname(n-1) ; if isprime(p) then 2*p; else p+1 ; end if; end if; end proc: A163963 := proc(n) A080735(n+1)-A080735(n) ; end: seq(A163963(n), n=1..100) ; # R. J. Mathar, Nov 05 2009 MATHEMATICA Differences@ NestList[If[PrimeQ@ #, 2 #, # + 1] &, 1, 87] (* Michael De Vlieger, Dec 06 2018, after Harvey P. Dale at A080735 *) PROG (PARI) lista(nn) = {my(va = vector(nn)); va[1] = 1; for (n=2, nn, va[n] = if (isprime(va[n-1]), 2*va[n-1], va[n-1]+1); ); vector(nn-1, n, va[n+1] - va[n]); } \\ Michel Marcus, Dec 06 2018 CROSSREFS Cf. A116533, A163961, A080735, A006992, A055496, A080359, A104272, A106108, A132199. Sequence in context: A115123 A132081 A054251 * A119763 A092142 A299161 Adjacent sequences:  A163960 A163961 A163962 * A163964 A163965 A163966 KEYWORD nonn AUTHOR Vladimir Shevelev, Aug 07 2009 EXTENSIONS More terms from R. J. Mathar, Nov 05 2009 STATUS approved

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Last modified October 20 10:45 EDT 2019. Contains 328257 sequences. (Running on oeis4.)