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A217556 Terms as well as ending/starting digits are of alternating parity; this is the lexicographically earliest injective sequence with this property. 4
1, 2, 3, 4, 5, 6, 7, 8, 9, 20, 11, 22, 13, 24, 15, 26, 17, 28, 19, 40, 31, 42, 33, 44, 35, 46, 37, 48, 39, 60, 51, 62, 53, 64, 55, 66, 57, 68, 59, 80, 71, 82, 73, 84, 75, 86, 77, 88, 79, 200, 91, 202, 93, 204, 95, 206, 97, 208, 99, 210, 101, 212, 103, 214, 105, 216, 107, 218, 109 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..69.

E. Angelini, Odd/even: integers and digits alternate, SeqFan mailing list, Oct 06 2012

PROG

(PARI) A217556(n, show=0, a=1, u)={for( i=2, n, u+=1<<a; show & print1(a", "); for(t=1, 9e9, bittest(u, t) & next; bittest(t+a, 0) || next; !bittest(a%10 + t\10^(#Str(t)-1), 0) & (t+=10^(#Str(t)-1)-1) & next; a=t; break )); a}  \\ - M. F. Hasler, Oct 06 2012

CROSSREFS

A simplified variant of A217555.

See also A217559, A217560, where "parity" is replaced by "primality".

Sequence in context: A048410 A180083 A275775 * A249873 A102491 A111706

Adjacent sequences:  A217553 A217554 A217555 * A217557 A217558 A217559

KEYWORD

nonn,base

AUTHOR

Eric Angelini and M. F. Hasler, Oct 06 2012

STATUS

approved

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Last modified January 28 00:32 EST 2020. Contains 331313 sequences. (Running on oeis4.)