A171703 The first n-fold intrinsically 4-palindromic number (represented in base ten).

9, 624, 19040, 30222192, 592704000, 12040481088, 128024064000, 1024192512000, 3456649728000

Offset

1,1

Comments

The fifth and sixth terms are both cubes, exploiting the simple binomial expansion as (m)(m)^3=(m^3)(3m^3)(3m^3)(m^3) for much of their status. - James G. Merickel, Dec 19 2009

The first base in which the fifth term is 4-palindromic is 209. - James G. Merickel, Dec 18 2009

a(10) <= 27653197824000, a(11) <= 27653197824000, a(12) <= 575100098496000, a(13) <= 1733189185728000, a(14) <= 1733189185728000, a(15) <= 8400090327552000. - Hiroaki Yamanouchi, Sep 24 2014

Links

Table of n, a(n) for n=1..9.

Example

a(2)=624 is 4444 in base 5 and 1551 in base 7.

Crossrefs

Cf. A171701, A171702, A171704, A171705, A171706, A171740, A171741, A171742.

Sequence in context: A139107 A226552 A277232 * A352276 A085530 A188423

Adjacent sequences: A171700 A171701 A171702 * A171704 A171705 A171706

Keyword

nonn,base

Author

James G. Merickel, Dec 16 2009

Extensions

a(5)-a(6) from James G. Merickel, Dec 19 2009

a(7)-a(9) from Hiroaki Yamanouchi, Sep 24 2014

Status

approved