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A235224 a(0) = 0, and for n > 0, a(n) = largest k such that A002110(k-1) <= n, where A002110(k) gives the k-th primorial number. 8
0, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

For n > 0: a(n) = (length of row n in A235168) = A055642(A049345(n)).

For n > 0, a(n) gives the length of primorial base expansion of n. Also, after zero, each value n occurs A061720(n-1) times. - Antti Karttunen, Oct 19 2019

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 0..10000

Index entries for sequences related to primorial base

FORMULA

From Antti Karttunen, Oct 19 2019: (Start)

a(n) = A061395(A276086(n)).

For all n >= 0, a(n) >= A267263(n).

For all n >= 1, A000040(a(n)) > A328114(n). (End)

PROG

(Haskell)

a235224 n = length $ takeWhile (<= n) a002110_list

(PARI) A235224(n) = { my(s=0, p=2); while(n, s++; n = n\p; p = nextprime(1+p)); (s); }; \\ Antti Karttunen, Oct 19 2019

(PARI) A235224(n, p=2) = if(!n, n, if(n<p, 1, 1+A235224(n\p, nextprime(p+1)))); \\ (Recursive implementation) - Antti Karttunen, Oct 19 2019

CROSSREFS

Cf. A000040, A002110, A049345, A055642, A061395, A061720, A084558, A267263, A276086, A235168, A328114, A328404, A328405, A328406.

Sequence in context: A321857 A186313 A165020 * A069624 A092139 A084558

Adjacent sequences:  A235221 A235222 A235223 * A235225 A235226 A235227

KEYWORD

nonn,changed

AUTHOR

Reinhard Zumkeller, Jan 05 2014

EXTENSIONS

Name corrected to match the data - Antti Karttunen, Oct 19 2019

STATUS

approved

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Last modified October 21 22:47 EDT 2019. Contains 328315 sequences. (Running on oeis4.)