A295430 a(n) is the least nontrivial multiple of n that begins with 3.

3, 30, 30, 32, 30, 30, 35, 32, 36, 30, 33, 36, 39, 308, 30, 32, 34, 36, 38, 300, 315, 308, 322, 312, 300, 312, 324, 308, 319, 300, 310, 320, 330, 306, 315, 324, 333, 304, 312, 320, 328, 336, 301, 308, 315, 322, 329, 336, 343, 300, 306, 312, 318, 324, 330, 336, 342, 348, 354, 300, 305, 310, 315

Offset

1,1

Links

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

Maple

f:= 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(f(i), i=1..100);

Prog

(PARI) a(n) = {my(k=2); while(digits(k*n)[1] != 3, k++); k*n; } \\ Michel Marcus, Feb 13 2018
(Python)
def A295430(n):
    m = 2*n
    while True:
        if str(m)[0] == '3':
            return m
        m += n # Chai Wah Wu, Feb 13 2018

Crossrefs

Cf. A082792.

Sequence in context: A154054 A118219 A186681 * A344430 A217395 A077679

Adjacent sequences: A295427 A295428 A295429 * A295431 A295432 A295433

Keyword

nonn

Author

Robert Israel, Feb 12 2018

Status

approved