A343816 a(n) is the least start of exactly n consecutive odd numbers that are cyclic numbers (A003277).

23, 41, 177, 1, 11, 877, 2387, 695

Offset

1,1

Comments

The sequence is restricted to odd cyclic numbers since 2 is the only even cyclic number.

This sequence is finite, with 8 terms; any run of 9 consecutive odd numbers will contain a multiple of 9, and this multiple of 9 cannot be cyclic. - Rémy Sigrist, May 10 2021

Links

Table of n, a(n) for n=1..8.

Example

a(1) = 23 since 23 is cyclic, but 21 and 25 are not.
a(2) = 41 since 41 and 43 are cyclic, but 39 and 45 are not.

Mathematica

cycQ[n_] := CoprimeQ[n, EulerPhi[n]]; seq[m_] := Module[{s = Table[0, {m}], c = 0, n = 1, n1, d}, While[c < m, n1 = n; If[cycQ[n], While[n1 += 2; cycQ[n1]]; d = (n1 - n)/2; If[d <= m && s[[d]] == 0, c++; s[[d]] = n]]; n = n1 + 2]; s]; seq[8]

Crossrefs

Cf. A003277, A343815.

Sequence in context: A114379 A345099 A106969 * A304390 A309533 A331342

Adjacent sequences: A343813 A343814 A343815 * A343817 A343818 A343819

Keyword

nonn,fini,full

Author

Amiram Eldar, Apr 30 2021

Status

approved