

A085944


Let S = 12345678901234567890123456..., the cyclic concatenation of digits; partition this string into distinct squarefree numbers. To avoid leading zeros, no member may end with the digit 9.


0



1, 2, 3, 4567, 890, 123, 45678, 901, 23, 4567890, 1234, 5, 6, 7, 89012345, 67, 89012345678, 90123, 45678901, 2345, 678, 901234, 5678, 9012345, 67890, 12345, 678901, 2345678, 901234567, 8901234567890, 1234567, 8901234567890123
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OFFSET

1,2


LINKS

Table of n, a(n) for n=1..32.


EXAMPLE

a(4) = 4567 because 4567 is squarefree, while 4, 45 and 456 are not.
a(5) = 890 because 89 would cause a(6) to have a leading 0.


PROG

(PARI) used = matrix(9, 60); x = 1; for (n = 1, 80, num = x; s = x; d = 1; while (used[s, d]  !issquarefree(num)  x == 9, x = (x + 1)%10; num = 10*num + x; d++); print(num); used[s, d] = 1; x++); (Wasserman)


CROSSREFS

Cf. A085943.
Sequence in context: A068661 A271631 A068826 * A137078 A146026 A115640
Adjacent sequences: A085941 A085942 A085943 * A085945 A085946 A085947


KEYWORD

base,nonn


AUTHOR

Amarnath Murthy, Jul 14 2003


EXTENSIONS

Corrected and extended by David Wasserman, Feb 14 2005


STATUS

approved



