A082792 Smallest multiple of n beginning with 3.

3, 30, 3, 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, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 320, 328, 336, 301, 308, 315, 322, 329, 336, 343, 300, 306, 312, 318, 324, 330, 336, 342, 348, 354

Offset: 1

Author

Amarnath Murthy, Apr 20 2003

Keywords

• base
• easy
• nonn

Comments

a(n) is in {n, 2n, 3n, 4n, 5n, 6n, 7n, 8n, 11n, 12n, 13n, 14n, 15n, 21n, 22n, 23n}. - Charles R Greathouse IV, Mar 06 2011

Links

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

Crossrefs

Cf. A082793, A082794, A082795, A082796.

Cf. A000030.

Programs

Haskell

a082792 n = until ((== 3) . a000030) (+ n) n
-- Reinhard Zumkeller, Mar 27 2012

Mathematica

f[n_] := Block[{m = n}, While[ First@ IntegerDigits@ m != 3, m += n]; m]; Array[f, 59] (* Robert G. Wilson v, Mar 06 2011 *)

PARI

a(n)=forstep(k=n,23*n,n,if(Vec(Str(k))[1]=="3",return(k))) \\ Charles R Greathouse IV, Mar 06 2011

Python

def a(n):
  kn = n
  while str(kn)[0] != '3': kn += n
  return kn
print([a(n) for n in range(1, 60)]) # Michael S. Branicky, Mar 30 2021

Extensions

Corrected and extended by Sean A. Irvine, Mar 06 2011