A048853 -id:A048853 - cp's OEIS frontend

A050670 Primes p such that number of primes produced according to rules stipulated in Honaker's A048853 is 8.

13, 103, 127, 173, 223, 257, 307, 317, 337, 367, 383, 397, 401, 419, 449, 461, 463, 491, 499, 557, 563, 577, 601, 613, 643, 647, 653, 673, 677, 683, 709, 739, 823, 829, 853, 887, 907, 967, 1033, 1063, 1087, 1103, 1163, 1213, 1217, 1223, 1277, 1307

Offset: 1

Patrick De Geest, Jul 15 1999

			Altering a(1)=13 gives 8 primes: 23, 43, 53, 73, 83, 11, 17 and 19.

Cf. A048853, A050673, A050659.

A050671 Primes p such that number of primes produced according to rules stipulated in Honaker's A048853 is 9.

Original entry on oeis.org

131, 137, 163, 167, 193, 199, 263, 283, 347, 431, 641, 757, 827, 883, 947, 997, 1021, 1051, 1061, 1109, 1151, 1187, 1193, 1237, 1259, 1279, 1283, 1289, 1453, 1549, 1583, 1627, 1637, 1663, 1669, 1823, 1867, 1901, 1907, 1997, 2003, 2029, 2083, 2099, 2339

Offset: 1

Patrick De Geest, Jul 15 1999

			Altering a(1)=131 gives 9 primes: 331, 431, 631, 101, 151, 181, 191, 137 and 139.

Cf. A048853, A050673, A050660.

A192545 Numbers such that all numbers are composite when replacing exactly one digit with another, except the leading digit with zero.

Original entry on oeis.org

200, 202, 204, 205, 206, 208, 320, 322, 324, 325, 326, 328, 510, 512, 514, 515, 516, 518, 530, 532, 534, 535, 536, 538, 620, 622, 624, 625, 626, 628, 840, 842, 844, 845, 846, 848, 890, 892, 894, 895, 896, 898, 1070, 1072, 1074, 1075, 1076, 1078, 1130, 1132

Offset: 1

Reinhard Zumkeller, Jul 05 2011

A048853(a(n)) = 0;
Intersection of this sequence and A000040 is A158124. - Evgeny Kapun, Dec 13 2016
If the last digit of an element is 0, 2, 4, 5, 6 or 8, then replacing it with 0, 2, 4, 5, 6 or 8 also yields an element. - David A. Corneth and corrected by Evgeny Kapun, Dec 13 2016

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Subsequences: A050249, A118118, A143641, A158124, A158125.

import Data.List (elemIndices)
a192545 n = a192545_list !! (n-1)
a192545_list = map (+ 1) $ elemIndices 0 $ map a048853 [1..]

Select[Range@ 1200, Function[w, Total@ Boole@ Flatten@ Map[Function[d, PrimeQ@ FromDigits@ ReplacePart[w, d -> #] & /@ If[d == 1, #, Prepend[#, 0]] &@ Range@ 9], Range@ Length@ w] == 0]@ IntegerDigits@ # &] (* Michael De Vlieger, Dec 13 2016 *)

cp's OEIS Frontend

A050670 Primes p such that number of primes produced according to rules stipulated in Honaker's A048853 is 8.

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A050671 Primes p such that number of primes produced according to rules stipulated in Honaker's A048853 is 9.

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Author

Keywords

Examples

Crossrefs

A192545 Numbers such that all numbers are composite when replacing exactly one digit with another, except the leading digit with zero.

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