

A227187


Numbers n whose factorial base representation A007623(n) contains at least one nonleading zero. (Zero is also included as a(0)).


4



0, 2, 4, 6, 7, 8, 10, 12, 13, 14, 16, 18, 19, 20, 22, 24, 25, 26, 27, 28, 29, 30, 31, 32, 34, 36, 37, 38, 40, 42, 43, 44, 46, 48, 49, 50, 51, 52, 53, 54, 55, 56, 58, 60, 61, 62, 64, 66, 67, 68, 70, 72, 73, 74, 75, 76, 77, 78, 79, 80, 82, 84, 85, 86, 88, 90, 91
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

0,2


LINKS

Antti Karttunen, Table of n, a(n) for n = 0..10000
Index entries for sequences related to factorial base representation


FORMULA

a(0) = 0, a(1) = 2, and for n > 1, if a(n1) is odd or A257510(a(n1)) > 1, then a(n) = a(n1) + 1, otherwise a(n) = a(n1) + 2.  Antti Karttunen, Apr 29 2015
Other identities:
For all n >= 2, a(A132371(n)) = A000142(n) = n! [See comments in A227157.]


PROG

(Scheme, with Antti Karttunen's IntSeqlibrary)
(define A227187 (ZEROPOS 0 0 A208575))
(definec (A227187 n) (if (<= n 1) (+ n n) (let ((prev (A227187 ( n 1)))) (cond ((odd? prev) (+ 1 prev)) ((> (A257510 prev) 1) (+ 1 prev)) (else (+ 2 prev))))))


CROSSREFS

Complement: A227157.
The sequence gives all positions n where A208575 is zero and all terms where A257510 (also A257260) are nonzeros.
Cf. A232745 (a subsequence), A232744.
Cf. also A007623, A132371, A153880, A227130, A227132, A256450 (numbers with at least one 1 in their factorial representation).
Sequence in context: A153347 A330945 A153167 * A047237 A285520 A039028
Adjacent sequences: A227184 A227185 A227186 * A227188 A227189 A227190


KEYWORD

nonn


AUTHOR

Antti Karttunen, Jul 04 2013


STATUS

approved



