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A076643 Integers read backwards, but omit a number if it is <= an earlier number. 0
1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 21, 31, 41, 51, 61, 71, 81, 91, 92, 93, 94, 95, 96, 97, 98, 99, 101, 201, 301, 401, 501, 601, 701, 801, 901, 911, 921, 931, 941, 951, 961, 971, 981, 991, 992, 993, 994, 995, 996, 997, 998, 999, 1001, 2001, 3001, 4001, 5001, 6001, 7001 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

EXAMPLE

The beginning list is 1,2,3,4,5,6,7,8,9,1,11; but 1<9 so omit it.

MAPLE

d := N->`if`(N=0, [0], ListTools[Reverse](convert(N, base, 10))); a := N->sum(d(N)[n]*10^(n-1), n=1..nops(d(N))); dropsort := proc(S)::list; description "Forms a strictly increasing list by dropping terms."; local T, V; T := k->max(seq(S[j], j=1..k)); V := ListTools[MakeUnique]([seq(T(j), j=1..nops(S))]); return(V); end proc; dropsort([seq(a(n), n=1..2000)]);

CROSSREFS

Cf. A004086.

Sequence in context: A161390 A096106 A076641 * A127204 A102235 A107272

Adjacent sequences:  A076640 A076641 A076642 * A076644 A076645 A076646

KEYWORD

easy,nonn,base

AUTHOR

Francois Jooste (phukraut(AT)hotmail.com), Oct 23 2002

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Last modified February 13 18:59 EST 2012. Contains 205535 sequences.