OFFSET
1,1
COMMENTS
When M is a q-digit term, then M is a divisor of 10^(q+1) + 1.
For each term k in A329914, there exist a set of numbers M_k which, when 1 is placed at both ends of M_k, the number M_k is multiplied by k. This sequence gives the smallest integer M(k) = M of each set {M_k}.
See A329914 for further information about these numbers.
REFERENCES
D. Wells, 112359550561797732809 entry, The Penguin Dictionary of Curious and Interesting Numbers. Penguin Books, NY, 1986, Revised edition 1997, p. 196.
EXAMPLE
A329914(1) = 21 and 21 * 91 = 1[91]1, and there is no integer < 91 that satisfies this relation, so a(1) = 91.
A329914(2) = 23 and 23 * 77 = 1[77]1, and there is no integer < 77 that satisfies this relation, so a(2) = 77.
A329914(5) = 33 and 33 * 4347826087 = 1[4347826087]1, and there is no integer < 4347826087 that satisfies this relation, so a(5) = 4347826087.
CROSSREFS
KEYWORD
nonn,base,fini,full
AUTHOR
Bernard Schott, Nov 24 2019
STATUS
approved