A075017 Smallest k such that the concatenation k, k+1,k+2,k+3 is divisible by n; or 0 if no such number exists.

1, 1, 3, 3, 2, 3, 2, 3, 3, 7, 8, 3, 7, 17, 12, 3, 5, 3, 19, 17, 24, 15, 17, 3, 22, 7, 3, 17, 17, 27, 6, 3, 15, 5, 2, 3, 9, 19, 15, 17, 15, 45, 44, 37, 12, 17, 39, 3, 45, 47, 21, 41, 52, 3, 37, 17, 57, 17, 62, 57, 53, 53, 66, 3, 7, 15, 2, 21, 63, 17, 12, 3, 6, 9, 72

Offset: 1

Author

Amarnath Murthy, Sep 01 2002

Keywords

• base
• nonn

Examples

			a(7) = 2 as 7 divides 2345.
		

Crossrefs

Cf. A075113, A075114, A075115, A075116.

Programs

PARI

isok(k, n) = my(v = Str(k)); for (j=1, 3, v = concat(v, Str(k+j))); (eval(v) % n) == 0;
a(n) = my(k=1); while (!isok(k, n), k++); k; \\ Michel Marcus, Jan 21 2017

Extensions

Corrected and extended by Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Apr 19 2003