A122138 -id:A122138 - cp's OEIS frontend

A122139 Primes from A122136 corresponding to the indices A122138.

2, 13, 19, 29, 29, 79, 47, 73, 163, 359, 5233, 20477, 811, 13859, 2203, 75997, 3331, 4457, 239087, 58061, 159097, 116041, 7487, 17929, 4547, 152657, 408787, 58313, 5563, 4783, 226199, 13729, 676763, 204641, 119293, 283979, 2210983, 7121, 433

Offset: 1

Alexander Adamchuk, Aug 21 2006

nonn

Cf. A122136, A122138, A024450, A002110.

Select[Table[Numerator[Sum[Prime[k]^2,{k,1,n}]/Product[Prime[k],{k,1,n}]],{n,1,200}],PrimeQ[ #1]&]

a(n) = A122136(A122138(n)).

A122136 Numerator of Sum[ Prime[k]^2, {k,1,n}] / Product[ Prime[k], {k,1,n}] = Numerator[ A024450[n] / A002110[n] ].

Original entry on oeis.org

2, 13, 19, 29, 104, 29, 111, 79, 778, 47, 73, 163, 1068, 359, 5233, 885, 142, 20477, 219, 811, 2524, 13859, 2203, 56387, 10966, 75997, 3331, 6537, 54968, 1, 23139, 4457, 87382, 681, 15449, 239087, 108, 58061, 159097, 116041, 1882, 995, 74901, 7487

Offset: 1

Alexander Adamchuk, Aug 21 2006

a(n) = 1 for n = {30,123,195,214,248,300,304,335,343,350,364,367,414,443,543,570,579,584,590,612,671,691,...} = A122137. a(n) is prime for n = {1,2,3,4,6,8,10,11,12,14,15,18,20,22,23,26,27,32,36,...} = A122138. Prime a(n) are listed in A122139 = {2,13,19,29,29,79,47,73,163,359,5233,20477,811,13859,2203,75997,3331,...}.

Cf. A122137, A122138, A122139.

Table[Numerator[Sum[Prime[k]^2,{k,1,n}]/Product[Prime[k],{k,1,n}]],{n,1,100}]

a(n) = Numerator[ Sum[ Prime[k]^2, {k,1,n}] / Product[ Prime[k], {k,1,n}] ].

A122137 Indices n such that A122136[n] = 1, or A024450[n] divides A002110[n].

Original entry on oeis.org

30, 123, 195, 214, 248, 300, 304, 335, 343, 350, 364, 367, 414, 443, 543, 570, 579, 584, 590, 612, 671, 691, 706, 707, 734, 780, 791, 799, 806, 810, 827, 836, 852, 880, 938, 960, 976, 1015, 1055, 1147, 1168, 1190, 1195, 1199, 1200, 1210, 1230, 1231, 1250

Offset: 1

Alexander Adamchuk, Aug 21 2006

nonn

Cf. A024450, A002110, A122136, A122138, A122139.

Do[f=Numerator[Sum[Prime[k]^2,{k,1,n}]/Product[Prime[k],{k,1,n}]];If[f==1,Print[n]],{n,1,10000}]

A122136[ a(n) ] = 1.

cp's OEIS Frontend

A122139 Primes from A122136 corresponding to the indices A122138.

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A122136 Numerator of Sum[ Prime[k]^2, {k,1,n}] / Product[ Prime[k], {k,1,n}] = Numerator[ A024450[n] / A002110[n] ].

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A122137 Indices n such that A122136[n] = 1, or A024450[n] divides A002110[n].

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