A070246 a(n) = lcm(n, R(n)) / gcd(n, R(n)), where R(n) (A004086) is the digit reversal of n.

1, 1, 1, 1, 1, 1, 1, 1, 1, 10, 1, 28, 403, 574, 85, 976, 1207, 18, 1729, 10, 28, 1, 736, 28, 1300, 403, 24, 574, 2668, 10, 403, 736, 1, 1462, 1855, 28, 2701, 3154, 403, 10, 574, 28, 1462, 1, 30, 736, 3478, 28, 4606, 10, 85, 1300, 1855, 30, 1, 3640, 475, 4930, 5605

Offset

1,10

Comments

a(1) = 1, a(18) = 18. Are there more terms for which a(k) = k?

In response to the above question, these are the terms, up to the 1000th term, for which a(k)=k: 1, 10, 18, 100, 180, 520, 1000. - Harvey P. Dale, Jan 20 2026

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Example

a(12) = lcm(12,21)/gcd(12,21) = 84/3 = 28.

Mathematica

r[n_] := FromDigits[ Reverse[ IntegerDigits[n]]]; Table[ LCM[n, r[n]] / GCD[n, r[n]], {n, 1, 65}]
Table[With[{r=IntegerReverse[n]}, LCM[n, r]/GCD[n, r]], {n, 60}] (* Harvey P. Dale, Jan 20 2026 *)

Crossrefs

Sequence in context: A221311 A391054 A361949 * A085044 A215268 A059022

Adjacent sequences: A070243 A070244 A070245 * A070247 A070248 A070249

Keyword

base,nonn

Author

Amarnath Murthy, May 09 2002

Extensions

Edited by Robert G. Wilson v, May 10 2002

Status

approved