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English flagpole sequence (see comments)
2

%I #30 Jun 10 2016 00:21:00

%S 1,7,3,6,5,11,8,9,2,13,4,10,12,16,15,26,14,18,17,19,20,111,21,25,22,

%T 23,24,28,38,30,27,29,31,37,33,32,42,34,35,36,39,40,41,43,45,47,44,46,

%U 54,48,49,51,57,50,52,53,112,55,58,56,59,60,61,63,65,67,64,62,74,66,68,69,70,71,72,73,75,76,77,78,79,86,84,81,94,83,80,82,85,87,88,89,98,93,90,91,92,95,96,97,105,99,100,102,101,103,104,106,108,107,109,110,113

%N English flagpole sequence (see comments)

%C a(1) = 1, fp = "one"; a(2) = smallest number not yet used whose English number-word contains letter #2 of fp (= 7, seveN), fp = "oneseven"; a(3) = smallest number not yet used whose English number-word contains letter #3 of fp (= 3, thrEe), fp = "oneseventhree"; etc. Number-word spaces, hyphens, commas, and the conjunctive 'and' are ignored.

%H Eric Angelini, <a href="http://www.cetteadressecomportecinquantesignes.com/Flagpole.htm">Flagpole</a>

%H E. Angelini, <a href="/A215693/a215693.pdf">Flagpole</a> [Cached copy, with permission]

%H Hans Havermann, <a href="http://chesswanks.com/num/flagpole/">Flagpole sections (number-word terms up to 1050000)</a>

%e Term #30419 of our sequence is 30419. The positions of the appended "thirtythousandfourhundrednineteen" in fp are letters #999990 to #1000022. Letters #1000000 - #1000004 of fp are S, A, N, D, F. At 999999, all numbers up to 999999 (and no numbers beyond) have been used. Therefore a(1000000) - a(1000004) are 1000006 (one million Six), 1001000 (one million one thousAnd), 1000000 (oNe million), 1000100 (one million one hunDred), and 1000004 (one million Four).

%K nonn,word

%O 1,2

%A _Eric Angelini_, _Hans Havermann_, Aug 27 2012