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A051919 Start with n, apply k->2k+1 until reach new record prime; sequence gives record primes. 4

%I

%S 3,7,11,31,79,191,223,8191,73727,81919,738197503,51539607551,

%T 3232601036663613174009984612954335460652964980182760163363015849805536730581466940964863

%N Start with n, apply k->2k+1 until reach new record prime; sequence gives record primes.

%e 0->1->3, new record prime 3 in 2 steps; 1->3->7, new record prime 7 in 2 steps; 2->5->11, new record prime 11 in 2 steps; 3->7->15->31, new record prime 31 in 3 steps; ...

%t f[0] = {start=0, k=3, steps=2}; f[n_] := f[n] = (k=start=f[n-1][[1]]+1; steps=0; While[!PrimeQ[k] || k <= f[n-1][[2]], k=2k+1; steps++]; {start, k, steps}); A051919 = Table[Print[f[n] // Last]; f[n], {n, 0, 12}][[All, 2]] (* _Jean-Fran├žois Alcover_, Dec 10 2014 *)

%Y Cf. A051918, A052333.

%K nice,nonn

%O 0,1

%A _N. J. A. Sloane_, Dec 18 1999

%E More terms from _Naohiro Nomoto_, May 21 2001, who reports that the next term is > 10^130.

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Last modified January 21 19:08 EST 2019. Contains 319350 sequences. (Running on oeis4.)