A118798 -id:A118798 - cp's OEIS frontend

A120099 Numbers n such that the closest primes surrounding 10^n are the same distance modulo 100.

17, 45, 87, 101, 112, 230, 270, 341, 468, 472, 473, 479, 517, 554, 555, 568, 650, 657, 663, 696, 718, 727, 810, 830, 836, 900, 917, 952, 984, 988, 1020, 1021, 1022, 1059, 1140, 1142, 1167, 1200, 1295, 1326, 1400, 1401, 1405, 1406, 1418, 1449, 1499, 1503, 1526

Offset: 1

Cino Hilliard and Robert G. Wilson v, Jun 08 2006

{3, 3}, 45 {9, 9}, 87 {373, 273}, 101 {3, 203}, 112 {207, 807}, 230 {753, 1053}, 270 {361, 861}, 341 {831, 1331}, 468 {301, 801}, 472 {1569, 2669}, 473 {99, 599}, 479 {109, 209}, 554 {937, 437}, 555 {151, 2151}, 568 {501, 801}, 650 {1999, 899}, 657 {1791, 291}, 663 {6333, 33},
{61, 1361}, 718 {5863, 1463}, 727 {273, 1073}, 810 {1591, 2891}, 830 {2853, 1253}, 836 {2809, 1209}, 900 {1873, 773}, 917 {693, 5393}, 952 {4827, 27}, 984 {1867, 2867}, 988 {753, 1053}, 1020 {793, 1193}, 1021 {1609, 6209}, 1022 {853, 1053} 1059 {5793, 1293}, 1140 {357, 4857},
{4329, 5829}, 1167 {1131, 3231}, 1200 {5227, 4127}, 1295 {5169, 2369}, 1326 {907, 4007}, 1400 {13317, 2517}, 1401 {10549, 2249}, 1405 {4329, 629}, 1406 {7477, 10277}, 1418 {841, 8741}, 1449 {2989, 3089}, 1499 {2001, 1901}, 1503 {439, 339}, 1526 {4603, 603}, 1534 {2409, 3209}, ...,.

Cf. A115564, A118798.

NextPrim[n_] := Block[{k = n + 1}, While[ !PrimeQ@k, k++ ]; k]; PrevPrim[n_] := Block[{k = n - 1}, While[ ! PrimeQ@k, k-- ]; k]; Do[ If[ Mod[ NextPrim[10^n], 100] == Mod[10^n - PrevPrim[10^n], 100], Print[{n, a, b}]], {n, 1320}]
Select[Range[1530],Mod[NextPrime[10^#]-10^#,100]==Mod[10^# -NextPrime[ 10^#,-1],100]&] (* Harvey P. Dale, Sep 24 2021 *)

A033873 (mod 100) == A033874 (mod 100).

More terms from Robert G. Wilson v, Jun 09 2006

Corrected (term 517 added) by Harvey P. Dale, Sep 25 2021

cp's OEIS Frontend

A120099 Numbers n such that the closest primes surrounding 10^n are the same distance modulo 100.

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