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A230405 a(n) = A000217(A230404(n+1)); the first differences of A219650. 6
1, 1, 3, 1, 1, 3, 1, 1, 3, 1, 1, 6, 1, 1, 3, 1, 1, 3, 1, 1, 3, 1, 1, 6, 1, 1, 3, 1, 1, 3, 1, 1, 3, 1, 1, 6, 1, 1, 3, 1, 1, 3, 1, 1, 3, 1, 1, 6, 1, 1, 3, 1, 1, 3, 1, 1, 3, 1, 1, 10, 1, 1, 3, 1, 1, 3, 1, 1, 3, 1, 1, 6, 1, 1, 3, 1, 1, 3, 1, 1, 3, 1, 1, 6, 1, 1, 3 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Construction: Count the trailing zeros in the factorial base representation (A007623) of 2n+2 (2, 4, 6, 8, ...) and then take the corresponding triangular number from A000217.

LINKS

Antti Karttunen, Table of n, a(n) for n = 0..10079

FORMULA

a(n) = A000217(A230404(n+1)).

a(n) = A219650(n+1) - A219650(n).

PROG

(Scheme, two variants)

(define (A230405 n) (A000217 (A230404 (+ 1 n))))

(define (A230405 n) (- (A219650 (+ n 1)) (A219650 n)))

CROSSREFS

First differences of A219650. Can be used to compute A219650 and A230412. Cf. also A230413.

Sequence in context: A109007 A132951 A228925 * A101685 A238737 A049653

Adjacent sequences:  A230402 A230403 A230404 * A230406 A230407 A230408

KEYWORD

nonn

AUTHOR

Antti Karttunen, Oct 31 2013

STATUS

approved

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Last modified September 20 17:41 EDT 2021. Contains 347588 sequences. (Running on oeis4.)