A230637 Leading power of 4 in A230638.

2, 7, 12, 5468, 10924, 5597880, 16777229

Offset

2,1

Comments

a(9) = ( 4^5468 + 2*4^12 + 39 ) / 3.

a(10) = 4^5468 + 13.

a(11) = ( 4^10924 + 2*4^5468 + 16407 ) / 3.

a(12) = 4^10924 + 10925

a(13) = ( 4^5597880 + 3*4^10924 + 32793 ) / 3.

a(14) = ( 2*4^5597880 + 32812 ) / 3.

a(15) = ( 4^16777229 + 4^5597880 + 2*4^12 + 16427 ) / 3.

a(16) = ( 2*4^16777229 + 4^13 + 42 ) / 3.

Links

Table of n, a(n) for n=2..8.

Max Alekseyev, Table n, expression for a(n) for n=2..100

Max A. Alekseyev and N. J. A. Sloane, On Kaprekar's Junction Numbers, arXiv:2112.14365, 2021; Journal of Combinatorics and Number Theory, 2022 (to appear).

Index entries for Colombian or self numbers and related sequences

Crossrefs

Cf. A230638.

Related base-4 sequences: A053737, A230631, A230632, A010064, A230633, A230634, A230635, A230636, A230637, A230638, A010065 (trajectory of 1)

Sequence in context: A353069 A046243 A230302 * A301852 A103886 A231900

Adjacent sequences: A230634 A230635 A230636 * A230638 A230639 A230640

Keyword

nonn,base

Author

N. J. A. Sloane, Oct 31 2013

Extensions

Terms a(8) onward from Max Alekseyev, Oct 31 2013

Status

approved