A114013 Least multiple of prime(n) ending in digit 9.

49, 99, 39, 119, 19, 69, 29, 279, 259, 369, 129, 329, 159, 59, 549, 469, 639, 219, 79, 249, 89, 679, 909, 309, 749, 109, 339, 889, 1179, 959, 139, 149, 1359, 1099, 489, 1169, 519, 179, 1629, 1719, 579, 1379, 199, 1899, 669, 1589, 229, 699, 239, 2169, 2259

Offset: 4

Author

Amarnath Murthy, Nov 12 2005

Keywords

• base
• nonn

Comments

Subsidiary sequences: (1) least multiple of prime(n) ending in 2 or 3 or ..., or 8; (2) divide the above sequences by prime(n).

Crossrefs

Cf. A114011, A114012.

Programs

Mathematica

f[n_] := Block[{k = 1, p = Prime[n]}, While[Mod[k*p, 10] != 9, k++ ]; k*p]; Table[ f[n], {n, 4, 54}] (* Robert G. Wilson v, Nov 17 2005 *)

PARI

a(n) = my(p=prime(n), k=1); while(((k*p) % 10) != 9, k++); k*p; \\ Michel Marcus, Jan 29 2023

Extensions

More terms from Robert G. Wilson v, Nov 17 2005