login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A133650 Early early bird numbers (early bird numbers of order 2). 3
99, 111, 122, 123, 132, 142, 152, 162, 172, 182, 192, 211, 212, 214, 215, 216, 217, 218, 219, 220, 221, 231, 232, 233, 234, 243, 253, 263, 273, 283, 293, 311, 312, 313, 321, 322, 323, 325, 326, 327, 328, 329, 330, 331, 332, 342, 343, 344, 345, 354, 364, 374 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

N-th Early bird number A116700(n) is in the sequence if it occurs in the concatenation of the first n-1 early bird numbers, A116700(1), ..., A116700(n-1).

With A116700 as early bird numbers of order 1, this can be generalized to define early bird numbers of order k for k > 1: N-th Early bird number of order k-1 is an early bird number of order k if it occurs in the concatenation of the first n-1 early bird numbers of order k-1.

Inspired by Eric Angelini's posting to Seq Fan mailing list, Jul 23, 2007.

LINKS

Klaus Brockhaus, Table of n, a(n) for n = 1..1000

EXAMPLE

A116700(45) = 99 occurs in the concatenation 1221233132344142434551525354566162636465677172737475767881828384858687899192939495969798 of A116700(1), ..., A116700(44). Hence 99 is an early bird number of order 2.

PROG

(JBASIC) Program works for order >= 1; set maxterm >= A133652(order).

order = 2

maxterm = 374 : dim seq(maxterm), early(maxterm)

for i = 1 to maxterm : seq(i) = i : next

for k = 1 to order

concatenation$ = "" : n = 0

for j = 1 to maxterm

term = seq(j) : string$ = str$(term)

if instr(concatenation$, string$) > 0 then n = n+1 : early(n) = term

concatenation$ = concatenation$ + string$

next j

maxterm = n : redim seq(maxterm)

for i = 1 to maxterm : seq(i) = early(i) : next

redim early(maxterm)

next k

print "early bird numbers of order "; order

for i = 1 to maxterm : print seq(i); ", "; : next

CROSSREFS

Cf. A116700 (early bird numbers), A133651 (early bird numbers of order 3), A133652 (least early bird number of order n).

Sequence in context: A171904 A171903 A072433 * A045298 A304951 A316619

Adjacent sequences:  A133647 A133648 A133649 * A133651 A133652 A133653

KEYWORD

nonn,base

AUTHOR

Klaus Brockhaus, Sep 19 2007

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified January 28 03:42 EST 2020. Contains 331317 sequences. (Running on oeis4.)