A078287 Least nontrivial multiple of the n-th prime beginning with 3.

30, 30, 30, 35, 33, 39, 34, 38, 322, 319, 310, 333, 328, 301, 329, 318, 354, 305, 335, 355, 365, 316, 332, 356, 388, 303, 309, 321, 327, 339, 381, 393, 3014, 3058, 3129, 302, 314, 326, 334, 346, 358, 362, 382, 386, 394, 398, 3165, 3122, 3178, 3206, 3029

Offset

1,1

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Maple

g := proc (n) local m, k;
  for m from 0 do
    k := max(2, ceil(3*10^m/n));
    if k*n < 4*10^m then return k*n end if
  end do
end proc:
seq(g(ithprime(i)), i=1..100); # Robert Israel, Feb 12 2018

Mathematica

f[n_] := Block[{k = 2, m = n}, While[ IntegerDigits[k*m][[1]] != 3, k++ ]; k*m]; Table[ f[ Prime[n]], {n, 1, 55}]

Prog

(PARI) a(n) = {my(k=2, p=prime(n)); while(digits(k*p)[1] != 3, k++); k*p; } \\ Michel Marcus, Feb 12 2018

Crossrefs

Cf. A078285, A078286, A078288, A078289, A078290, A078291, A078292, A078293.

Sequence in context: A056997 A056958 A010869 * A220440 A040871 A022364

Adjacent sequences: A078284 A078285 A078286 * A078288 A078289 A078290

Keyword

base,easy,nonn,look

Author

Amarnath Murthy, Nov 26 2002

Extensions

Edited, corrected and extended by Robert G. Wilson v, Nov 29 2002

Status

approved