A194635 -id:A194635 - cp's OEIS frontend

A194607 Record values in A194606.

0, 1, 2, 4, 5, 6, 11, 17, 20, 28, 70, 99, 150, 726, 7431, 22394, 85461, 191207

Offset: 1

Arkadiusz Wesolowski, Aug 30 2011

The index sequence of this one is 1, 3, 6, 15, 17, 29, 53, 115, 186, 220, 229, 1886, 5344, 5736, 66774, 1087403, 14747671, 158018119.

a(17) was found in 2000 by Wilfrid Keller and a(18) was found in 2003 by Patrick De Geest.

			A194606(53) = 11 since A194606(115) = 17 is the next record value.

Wilfrid Keller, personal communication, 2010.

Chris K. Caldwell, The List of Largest Known Primes, 270704167 * 2^85461 - 1
Chris K. Caldwell, The List of Largest Known Primes, 3296757029 * 2^191207 + 1
Carlos Rivera, Problem 30

Cf. A194591, A194600, A194603, A194606, A194608, A194635, A194636, A194637, A194638, A194639.

Cf. A103963, A103964, A076335, A180247.

l = -1; Flatten[Table[p = Prime[n]; k = 0; While[! PrimeQ[p*2^k - 1] && ! PrimeQ[p*2^k + 1], k++]; If[k > l, l = k, {}], {n, 10^4}]] (* Arkadiusz Wesolowski, Sep 04 2011 *)

A194637 Record values in A194636.

Original entry on oeis.org

0, 1, 2, 4, 5, 6, 11, 18, 20, 28, 70, 106, 150, 726, 2906, 7431, 14073, 22394, 41422, 82587, 85461, 356981

Offset: 1

Arkadiusz Wesolowski, Aug 31 2011

The index sequence is 1, 3, 7, 24, 30, 55, 121, 168, 555, 687, 724, 7447, 26134, 28272, 324802, 419221, 4420051, 8467881, 50302257, 59186640, 135352084, 677738616, ... given by formula (A194639(n)+1)/2.

			A194636(55) = 6 since A194636(121) = 11 is the next record value.

Wilfrid Keller, personal communication, 2010.

Chris K. Caldwell, The List of Largest Known Primes, 1355477231 * 2^356981 + 1
Carlos Rivera, Problem 30

Cf. A194591, A194600, A194603, A194606, A194607, A194608, A194635, A194636, A194638, A194639.

Cf. A103963, A103964, A076335, A180247.

l = -1; Flatten[Table[n = 2*n - 1; k = 0; While[! PrimeQ[n*2^k - 1] && ! PrimeQ[n*2^k + 1], k++]; If[k > l, l = k, {}], {n, 10^5}]] (* Arkadiusz Wesolowski, Sep 04 2011 *)

a(n) = A194591(A194639(n)) = A194636((A194639(n)+1)/2).

a(22) was found in 2002 by Wilfrid Keller.

A217892 Indices of records in A194591.

Original entry on oeis.org

1, 5, 13, 47, 59, 109, 241, 335, 1109, 1373, 1447, 14893, 37892, 56543, 185644, 649603, 838441, 8840101, 16935761, 100604513, 118373279, 270704167, 1355477231

Offset: 1

Max Alekseyev, Oct 14 2012

Record values are given by A194600.

Cf. A194635, A194639, A194600.

a[n_]:= (k=0; While[!PrimeQ[n*2^k-1] && !PrimeQ[n*2^k+1], k++]; k); w = {1}; v = {0}; Do[If[a[n]>v[[-1]], AppendTo[v, a[n]]; Print[n]], {n, 1356000000}] (* Farideh Firoozbakht, Oct 16 2014 *)

a(23)=A194639(22) from Wilfrid Keller, added by Max Alekseyev, Oct 18 2014

cp's OEIS Frontend

A194607 Record values in A194606.

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A194637 Record values in A194636.

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A217892 Indices of records in A194591.

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