A257692 Numbers such that the smallest nonzero digit present (A257679) in their factorial base representation is 2.

4, 12, 16, 22, 48, 52, 60, 64, 66, 70, 76, 84, 88, 94, 100, 108, 112, 118, 240, 244, 252, 256, 258, 262, 288, 292, 300, 304, 306, 310, 312, 316, 324, 328, 330, 334, 336, 340, 348, 352, 354, 358, 364, 372, 376, 382, 408, 412, 420, 424, 426, 430, 436, 444, 448, 454, 460, 468, 472, 478, 484, 492, 496, 502

Offset

1,1

Comments

Numbers k for which A257679(k) = 2.

Links

Antti Karttunen, Table of n, a(n) for n = 1..10000

Index entries for sequences related to factorial base representation.

Example

Factorial base representation (A007623) of 22 is "320" as 22 = 3*3! + 2*2! + 0*1!, thus a(22) = 2.

Mathematica

q[n_] := Module[{k = n, m = 2, r, s = {}}, While[{k, r} = QuotientRemainder[k, m]; k != 0|| r != 0, AppendTo[s, r]; m++]; !MemberQ[s, 1] && MemberQ[s, 2]]; Select[Range[500], q] (* Amiram Eldar, Feb 14 2024 *)

Prog

(Scheme, with Antti Karttunen's IntSeq-library)
(define A257692 (MATCHING-POS 1 1 (lambda (n) (= 2 (A257679 n)))))
(Python)
def A(n, p=2): return n if n<p else A(n//p, p+1)*10 + n%p
def a(n): return 0 if n==0 else min([int(i) for i in str(A(n)) if i !='0'])
print([n for n in range(1, 503) if a(n)==2]) # Indranil Ghosh, Jun 19 2017

Crossrefs

Row 2 of A257503.

Cf. A007623, A257679, A257693.

Cf. also A257262.

Sequence in context: A081523 A310567 A310568 * A053006 A328849 A261958

Adjacent sequences: A257689 A257690 A257691 * A257693 A257694 A257695

Keyword

nonn,base

Author

Antti Karttunen, May 04 2015

Status

approved