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A276091 Numbers obtained by reinterpreting base-2 representation of n in A001563-base (A276326): a(n) = Sum_k>=0 {A030308(n,k)*A001563(k+1)}. 13
0, 1, 4, 5, 18, 19, 22, 23, 96, 97, 100, 101, 114, 115, 118, 119, 600, 601, 604, 605, 618, 619, 622, 623, 696, 697, 700, 701, 714, 715, 718, 719, 4320, 4321, 4324, 4325, 4338, 4339, 4342, 4343, 4416, 4417, 4420, 4421, 4434, 4435, 4438, 4439, 4920, 4921, 4924, 4925, 4938, 4939, 4942, 4943, 5016, 5017, 5020, 5021, 5034, 5035, 5038, 5039, 35280, 35281 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Numbers that are sums of distinct terms of A001563.

A number is included if and only if all the nonzero digits in its factorial base representation (A007623) are maximal allowed in those digit positions, thus this sequence gives all numbers n for which A060130(n) = A260736(n).

Numbers n for which A276328(n) = A276337(n), thus from 1 onward the positions of ones in A276336.

Conjectured to give also all numbers n for which A255411(n) = A276340(n) (thus zeros of A276339).

LINKS

Antti Karttunen, Table of n, a(n) for n = 0..8191

Index entries for sequences related to factorial base representation

FORMULA

a(0) = 0, a(2n) = A255411(a(n)), a(2n+1) = 1+A255411(a(n)).

a(0) = 0, a(2n) = A276340(a(n)), a(2n+1) = 1+A276340(a(n)).

Other identities. For all n >= 0:

a(n) = A225901(A059590(n)).

a(n) = A276090(A275959(n)).

A276328(a(n)) = A276337(a(n)) = A000120(n).

MATHEMATICA

Table[Total[Times @@@ Transpose@ {Map[# #! &, Range@ Length@ #], Reverse@ #}] &@ IntegerDigits[n, 2], {n, 64}] (* Michael De Vlieger, Aug 31 2016 *)

PROG

(Scheme)

;; This is a standalone program:

(define (A276091 n) (let loop ((n n) (s 0) (f 1) (i 2)) (cond ((zero? n) s) ((even? n) (loop (/ n 2) s (* i f) (+ 1 i))) (else (loop (/ (- n 1) 2) (+ s (* (- i 1) f)) (* i f) (+ 1 i))))))

;; This implements one of the given recurrences:

(definec (A276091 n) (cond ((zero? n) n) ((even? n) (A255411 (A276091 (/ n 2)))) (else (+ 1 (A255411 (A276091 (/ (- n 1) 2)))))))

;; Alternatively, we can use A276340 in place of A255411:

(definec (A276091 n) (cond ((zero? n) n) ((even? n) (A276340 (A276091 (/ n 2)))) (else (+ 1 (A276340 (A276091 (/ (- n 1) 2)))))))

(Python)

from sympy import factorial as f

def a007623(n, p=2): return n if n<p else a007623(n//p, p+1)*10 + n%p

def a255411(n):

    x=(str(a007623(n)) + '0')

    y="".join(str(int(i) + 1) if int(i)>0 else '0' for i in x)[::-1]

    return 0 if n==0 else sum(int(y[i])*f(i + 1) for i in range(len(y)))

def a(n): return 0 if n==0 else a255411(a(n//2)) if n%2==0 else 1 + a255411(a((n - 1)//2))

print([a(n) for n in range(101)]) # Indranil Ghosh, Jun 20 2017

CROSSREFS

Cf. A000120, A000142, A001563, A030308, A059590, A060130, A260736, A225901, A255411, A275959, A276082, A276083, A276090, A276326, A276328, A276336, A276337, A276339, A276340.

Sequence in context: A060289 A215024 A066879 * A258410 A299241 A134750

Adjacent sequences:  A276088 A276089 A276090 * A276092 A276093 A276094

KEYWORD

nonn,base

AUTHOR

Antti Karttunen, Aug 19 2016

EXTENSIONS

Name changed (to emphasize the functional nature of the sequence) with the original definition moved to the comments by Antti Karttunen, Sep 01 2016

STATUS

approved

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Last modified September 23 07:41 EDT 2021. Contains 347609 sequences. (Running on oeis4.)