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A257804 Positions of even numbers in A233271, the infinite trunk of inverted binary beanstalk. 10
0, 2, 3, 5, 6, 8, 10, 11, 13, 14, 15, 16, 19, 20, 22, 26, 28, 29, 31, 32, 33, 36, 37, 39, 40, 43, 44, 45, 46, 47, 48, 50, 51, 56, 58, 59, 61, 62, 63, 66, 67, 69, 71, 72, 78, 79, 80, 84, 85, 86, 87, 88, 89, 91, 92, 94, 97, 98, 99, 100, 101, 102, 104, 105, 110, 112, 113, 115, 116, 117, 120, 121, 123, 124, 125, 126, 129, 130 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

We start indexing of this sequence from 0, because a(0) = 0 is a special case, which can be conveniently ignored by considering only the terms from a(1) onward.

LINKS

Antti Karttunen, Table of n, a(n) for n = 0..8433

FORMULA

Other identities. For all n >= 0:

A257808(a(n)) = n. [A257808 works as a left inverse for this injective function.]

PROG

(Scheme, with Antti Karttunen's IntSeq-library)

(define A257804 (MATCHING-POS 0 0 (lambda (n) (even? (A233271 n)))))

(define A257804 (MATCHING-POS 0 0 (lambda (n) (even? (A257800 n)))))

CROSSREFS

Complement: A257803.

Cf. A233271, A257800, A257806, A257808.

Sequence in context: A233592 A320773 A138390 * A285209 A184590 A047448

Adjacent sequences:  A257801 A257802 A257803 * A257805 A257806 A257807

KEYWORD

nonn

AUTHOR

Antti Karttunen, May 12 2015

STATUS

approved

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Last modified December 7 03:00 EST 2019. Contains 329836 sequences. (Running on oeis4.)