A354165 -id:A354165 - cp's OEIS frontend

A354164 Indices of nonprimes in A090252.

1, 5, 7, 11, 14, 15, 23, 29, 31, 32, 47, 59, 60, 63, 65, 95, 96, 119, 120, 121, 127, 128, 131, 132, 191, 193, 239, 241, 243, 244, 255, 257, 263, 264, 265, 383, 387, 388, 479, 480, 483, 484, 487, 488, 489, 511, 512, 515, 527, 529, 531, 571, 767, 775, 776, 777, 959, 960, 961, 967, 968, 969, 975, 976, 977, 979, 980, 1023, 1031, 1055, 1056, 1059, 1063

Offset: 1

N. J. A. Sloane, May 31 2022

nonn

Russ Cox, Table of n, a(n) for n = 1..3527 (first 374 terms from N. J. A. Sloane)
Russ Cox, Table of nonprime entries in A090252: n, A090252(n), # of prime factors, n = 1..3527.
Hugo van der Sanden, Table of nonprime entries in the first 10^9 terms of A090252. [See file header for description]

Cf. A090252, A354148, A354165, A354166.

A354166 Number of nonprimes among first n terms of A090252.

Original entry on oeis.org

1, 1, 1, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 5, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 8, 8, 9, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 12, 13, 13, 13, 14, 14, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 16, 17

Offset: 1

N. J. A. Sloane, May 31 2022

nonn

It appears that this sequence controls the growth of A090252. That is, almost all the terms of A090252 lie on the line A090252(n) = k-th prime, where k = n - a(n).

N. J. A. Sloane, Table of n, a(n) for n = 1..34886

Cf. A090252, A354164, A354165.

A355012 Prime powers (p^k, k >= 2) in A090252 in order of appearance.

Original entry on oeis.org

4, 9, 8, 25, 16, 27, 49, 121, 32, 169, 125, 289, 81, 361, 529, 64, 841, 343, 961, 128, 1369, 1681, 1849, 2209, 243, 2809, 3721, 4489, 5041, 5329, 1331, 6241, 6889, 3481, 256, 10609, 11449, 11881, 625, 12769, 7921, 9409, 10201, 2197, 26569, 32041, 32761, 16129

Offset: 1

Michael De Vlieger, Jun 15 2022

nonn

Michael De Vlieger, Table of n, a(n) for n = 1..1009
Michael De Vlieger, Annotated log-log scatterplot of A090252(n), n = 1..2^12, labeling primes in red, squarefree semiprimes in green, highlighting composite prime powers in gold and labeling them in boldface.

Cf. A090252, A246547, A354165, A355013, A355014.

Select[Import["https://oeis.org/A090252/b090252.txt", "Data"][[1 ;; 4000, -1]], CompositeQ[#] && PrimePowerQ[#] &]

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A354164 Indices of nonprimes in A090252.

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A354166 Number of nonprimes among first n terms of A090252.

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A355012 Prime powers (p^k, k >= 2) in A090252 in order of appearance.

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