cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-7 of 7 results.

A328629 Lexicographically earliest infinite sequence such that a(i) = a(j) => A046523(A328627(i)) = A046523(A328627(j)) for all i, j.

Original entry on oeis.org

1, 2, 2, 3, 4, 5, 2, 5, 6, 7, 8, 9, 4, 3, 5, 10, 11, 12, 13, 6, 14, 15, 3, 16, 17, 14, 3, 18, 19, 15, 2, 5, 5, 15, 3, 12, 14, 16, 18, 20, 21, 22, 23, 24, 16, 25, 26, 27, 19, 18, 28, 29, 10, 30, 31, 28, 24, 32, 33, 34, 4, 3, 3, 7, 8, 15, 5, 12, 28, 32, 33, 30, 19, 18, 12, 35, 36, 37, 31, 28, 38, 39, 15, 40, 41, 38, 18, 25, 26, 22, 13, 6, 6, 18, 19, 9, 42
Offset: 0

Views

Author

Antti Karttunen, Oct 25 2019

Keywords

Comments

Restricted growth sequence transform of function f(n) = A046523(A328627(n)), or equally, of function g(n) = A278226(A328626(n)).

Crossrefs

Programs

  • PARI
    up_to = 32768;
    rgs_transform(invec) = { my(om = Map(), outvec = vector(length(invec)), u=1); for(i=1, length(invec), if(mapisdefined(om,invec[i]), my(pp = mapget(om, invec[i])); outvec[i] = outvec[pp] , mapput(om,invec[i],i); outvec[i] = u; u++ )); outvec; };
    A046523(n) = { my(f=vecsort(factor(n)[, 2], , 4), p); prod(i=1, #f, (p=nextprime(p+1))^f[i]); }; \\ From A046523
    A328627(n) = { my(m=1, p=2, d=0); while(n, d = lift(Mod(n,p)/(d+1)); m *= (p^d); n = n\p; p = nextprime(1+p)); (m); };
    Aux328629(n) = A046523(A328627(n));
    v328629 = rgs_transform(vector(1+up_to, n, Aux328629(n-1)));
    A328629(n) = v328629[1+n];

A344762 "Twisted variant" of A342002: a(n) = A342001(A328627(n)) = A342002(A328626(n)).

Original entry on oeis.org

0, 1, 1, 7, 2, 5, 1, 7, 14, 47, 16, 43, 2, 9, 8, 59, 22, 31, 3, 11, 17, 41, 13, 49, 4, 13, 11, 53, 19, 37, 1, 9, 10, 55, 17, 41, 27, 89, 128, 479, 187, 361, 39, 113, 116, 503, 199, 337, 31, 97, 164, 407, 151, 433, 43, 121, 152, 431, 163, 409, 2, 11, 13, 61, 20, 47, 12, 59, 158, 419, 157, 421, 29, 93, 71, 593, 244, 247, 41
Offset: 0

Views

Author

Antti Karttunen, May 29 2021

Keywords

Crossrefs

Cf. also A344761 (another variant based on inverse of A328626).

Programs

  • PARI
    A328627(n) = { my(m=1, p=2, d=0); while(n, d = lift(Mod(n,p)/(d+1)); m *= (p^d); n = n\p; p = nextprime(1+p)); (m); };
    A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
    A003557(n) = (n/factorback(factorint(n)[, 1]));
    A342001(n) = (A003415(n) / A003557(n));
    A344762(n) = A342001(A328627(n));

Formula

a(n) = A342001(A328627(n)) = A342002(A328626(n)).

A276086 Primorial base exp-function: digits in primorial base representation of n become the exponents of successive prime factors whose product a(n) is.

Original entry on oeis.org

1, 2, 3, 6, 9, 18, 5, 10, 15, 30, 45, 90, 25, 50, 75, 150, 225, 450, 125, 250, 375, 750, 1125, 2250, 625, 1250, 1875, 3750, 5625, 11250, 7, 14, 21, 42, 63, 126, 35, 70, 105, 210, 315, 630, 175, 350, 525, 1050, 1575, 3150, 875, 1750, 2625, 5250, 7875, 15750, 4375, 8750, 13125, 26250, 39375, 78750, 49, 98, 147, 294, 441, 882, 245, 490, 735, 1470, 2205, 4410, 1225, 2450
Offset: 0

Views

Author

Antti Karttunen, Aug 21 2016

Keywords

Comments

Prime product form of primorial base expansion of n.
Sequence is a permutation of A048103. It maps the smallest prime not dividing n to the smallest prime dividing n, that is, A020639(a(n)) = A053669(n) holds for all n >= 1.
The sequence satisfies the exponential function identity, a(x + y) = a(x) * a(y), whenever A329041(x,y) = 1, that is, when adding x and y together will not generate any carries in the primorial base. Examples of such pairs of x and y are A328841(n) & A328842(n), and also A328770(n) (when added with itself). - Antti Karttunen, Oct 31 2019
From Antti Karttunen, Feb 18 2022: (Start)
The conjecture given in A327969 asks whether applying this function together with the arithmetic derivative (A003415) in some combination or another can eventually transform every positive integer into zero.
Another related open question asks whether there are any other numbers than n=6 such that when starting from that n and by iterating with A003415, one eventually reaches a(n). See comments in A351088.
This sequence is used in A351255 to list the terms of A099308 in a different order, by the increasing exponents of the successive primes in their prime factorization. (End)
From Bill McEachen, Oct 15 2022: (Start)
From inspection, the least significant decimal digits of a(n) terms form continuous chains of 30 as follows. For n == i (mod 30), i=0..5, there are 6 ordered elements of these 8 {1,2,3,6,9,8,7,4}. Then for n == i (mod 30), i=6..29, there are 12 repeated pairs = {5,0}.
Moreover, when the individual elements of any of the possible groups of 6 are transformed via (7*digit) (mod 10), the result matches one of the other 7 groupings (not all 7 may be seen). As example, {1,2,3,6,9,8} transforms to {7,4,1,2,3,6}. (End)
The least significant digit of a(n) in base 4 is given by A353486, and in base 6 by A358840. - Antti Karttunen, Oct 25 2022, Feb 17 2024

Examples

			For n = 24, which has primorial base representation (see A049345) "400" as 24 = 4*A002110(2) + 0*A002110(1) + 0*A002110(0) = 4*6 + 0*2 + 0*1, thus a(24) = prime(3)^4 * prime(2)^0 * prime(1)^0 = 5^4 = 625.
For n = 35 = "1021" as 35 = 1*A002110(3) + 0*A002110(2) + 2*A002110(1) + 1*A002110(0) = 1*30 + 0*6 + 2*2 + 1*1, thus a(35) = prime(4)^1 * prime(2)^2 * prime(1) = 7 * 3*3 * 2 = 126.
		

Crossrefs

Cf. A276085 (a left inverse) and also A276087, A328403.
Cf. A048103 (terms sorted into ascending order), A100716 (natural numbers not present in this sequence).
Cf. A278226 (associated filter-sequence), A286626 (and its rgs-version), A328477.
Cf. A328316 (iterates started from zero).
Cf. A327858, A327859, A327860, A327963, A328097, A328098, A328099, A328110, A328112, A328382 for various combinations with arithmetic derivative (A003415).
Cf. also A327167, A329037.
Cf. A019565 and A054842 for base-2 and base-10 analogs and A276076 for the analogous "factorial base exp-function", from which this differs for the first time at n=24, where a(24)=625 while A276076(24)=7.
Cf. A327969, A351088, A351458 for sequences with conjectures involving this sequence.

Programs

  • Mathematica
    b = MixedRadix[Reverse@ Prime@ Range@ 12]; Table[Function[k, Times @@ Power @@@ # &@ Transpose@ {Prime@ Range@ Length@ k, Reverse@ k}]@ IntegerDigits[n, b], {n, 0, 51}] (* Michael De Vlieger, Aug 23 2016, Version 10.2 *)
    f[n_] := Block[{a = {{0, n}}}, Do[AppendTo[a, {First@ #, Last@ #} &@ QuotientRemainder[a[[-1, -1]], Times @@ Prime@ Range[# - i]]], {i, 0, #}] &@ NestWhile[# + 1 &, 0, Times @@ Prime@ Range[# + 1] <= n &]; Rest[a][[All, 1]]]; Table[Times @@ Flatten@ MapIndexed[Prime[#2]^#1 &, Reverse@ f@ n], {n, 0, 73}] (* Michael De Vlieger, Aug 30 2016, Pre-Version 10 *)
    a[n0_] := Module[{m = 1, i = 1, n = n0, p}, While[n > 0, p = Prime[i]; m *= p^Mod[n, p]; n = Quotient[n, p]; i++]; m];
    Table[a[n], {n, 0, 100}] (* Jean-François Alcover, Dec 01 2021, after Antti Karttunen's Sage code *)
  • PARI
    A276086(n) = { my(i=0,m=1,pr=1,nextpr); while((n>0),i=i+1; nextpr = prime(i)*pr; if((n%nextpr),m*=(prime(i)^((n%nextpr)/pr));n-=(n%nextpr));pr=nextpr); m; }; \\ Antti Karttunen, May 12 2017
    
  • PARI
    A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); }; \\ (Better than above one, avoids unnecessary construction of primorials). - Antti Karttunen, Oct 14 2019
    
  • Python
    from sympy import prime
    def a(n):
        i=0
        m=pr=1
        while n>0:
            i+=1
            N=prime(i)*pr
            if n%N!=0:
                m*=(prime(i)**((n%N)/pr))
                n-=n%N
            pr=N
        return m # Indranil Ghosh, May 12 2017, after Antti Karttunen's PARI code
    
  • Python
    from sympy import nextprime
    def a(n):
        m, p = 1, 2
        while n > 0:
            n, r = divmod(n, p)
            m *= p**r
            p = nextprime(p)
        return m
    print([a(n) for n in range(74)])  # Peter Luschny, Apr 20 2024
  • Sage
    def A276086(n):
        m=1
        i=1
        while n>0:
            p = sloane.A000040(i)
            m *= (p**(n%p))
            n = floor(n/p)
            i += 1
        return (m)
    # Antti Karttunen, Oct 14 2019, after Indranil Ghosh's Python code above, and my own leaner PARI code from Oct 14 2019. This avoids unnecessary construction of primorials.
    
  • Scheme
    (define (A276086 n) (let loop ((n n) (t 1) (i 1)) (if (zero? n) t (let* ((p (A000040 i)) (d (modulo n p))) (loop (/ (- n d) p) (* t (expt p d)) (+ 1 i))))))
    
  • Scheme
    (definec (A276086 n) (if (zero? n) 1 (* (expt (A053669 n) (A276088 n)) (A276086 (A276093 n))))) ;; Needs macro definec from http://oeis.org/wiki/Memoization#Scheme
    
  • Scheme
    (definec (A276086 n) (if (zero? n) 1 (* (A053669 n) (A276086 (- n (A002110 (A276084 n))))))) ;; Needs macro definec from http://oeis.org/wiki/Memoization#Scheme
    

Formula

a(0) = 1; for n >= 1, a(n) = A053669(n) * a(A276151(n)) = A053669(n) * a(n-A002110(A276084(n))).
a(0) = 1; for n >= 1, a(n) = A053669(n)^A276088(n) * a(A276093(n)).
a(n) = A328841(a(n)) + A328842(a(n)) = A328843(n) + A328844(n).
a(n) = a(A328841(n)) * a(A328842(n)) = A328571(n) * A328572(n).
a(n) = A328475(n) * A328580(n) = A328476(n) + A328580(n).
a(A002110(n)) = A000040(n+1). [Maps primorials to primes]
a(A143293(n)) = A002110(n+1). [Maps partial sums of primorials to primorials]
a(A057588(n)) = A276092(n).
a(A276156(n)) = A019565(n).
a(A283477(n)) = A324289(n).
a(A003415(n)) = A327859(n).
Here the text in brackets shows how the right hand side sequence is a function of the primorial base expansion of n:
A001221(a(n)) = A267263(n). [Number of nonzero digits]
A001222(a(n)) = A276150(n). [Sum of digits]
A067029(a(n)) = A276088(n). [The least significant nonzero digit]
A071178(a(n)) = A276153(n). [The most significant digit]
A061395(a(n)) = A235224(n). [Number of significant digits]
A051903(a(n)) = A328114(n). [Largest digit]
A055396(a(n)) = A257993(n). [Number of trailing zeros + 1]
A257993(a(n)) = A328570(n). [Index of the least significant zero digit]
A079067(a(n)) = A328620(n). [Number of nonleading zeros]
A056169(a(n)) = A328614(n). [Number of 1-digits]
A056170(a(n)) = A328615(n). [Number of digits larger than 1]
A277885(a(n)) = A328828(n). [Index of the least significant digit > 1]
A134193(a(n)) = A329028(n). [The least missing nonzero digit]
A005361(a(n)) = A328581(n). [Product of nonzero digits]
A072411(a(n)) = A328582(n). [LCM of nonzero digits]
A001055(a(n)) = A317836(n). [Number of carry-free partitions of n in primorial base]
Various number theoretical functions applied:
A000005(a(n)) = A324655(n). [Number of divisors of a(n)]
A000203(a(n)) = A324653(n). [Sum of divisors of a(n)]
A000010(a(n)) = A324650(n). [Euler phi applied to a(n)]
A023900(a(n)) = A328583(n). [Dirichlet inverse of Euler phi applied to a(n)]
A069359(a(n)) = A329029(n). [Sum a(n)/p over primes p dividing a(n)]
A003415(a(n)) = A327860(n). [Arithmetic derivative of a(n)]
Other identities:
A276085(a(n)) = n. [A276085 is a left inverse]
A020639(a(n)) = A053669(n). [The smallest prime not dividing n -> the smallest prime dividing n]
A046523(a(n)) = A278226(n). [Least number with the same prime signature as a(n)]
A246277(a(n)) = A329038(n).
A181819(a(n)) = A328835(n).
A053669(a(n)) = A326810(n), A326810(a(n)) = A328579(n).
A257993(a(n)) = A328570(n), A328570(a(n)) = A328578(n).
A328613(a(n)) = A328763(n), A328620(a(n)) = A328766(n).
A328828(a(n)) = A328829(n).
A053589(a(n)) = A328580(n). [Greatest primorial number which divides a(n)]
A276151(a(n)) = A328476(n). [... and that primorial subtracted from a(n)]
A111701(a(n)) = A328475(n).
A328114(a(n)) = A328389(n). [Greatest digit of primorial base expansion of a(n)]
A328389(a(n)) = A328394(n), A328394(a(n)) = A328398(n).
A235224(a(n)) = A328404(n), A328405(a(n)) = A328406(n).
a(A328625(n)) = A328624(n), a(A328626(n)) = A328627(n). ["Twisted" variants]
a(A108951(n)) = A324886(n).
a(n) mod n = A328386(n).
a(a(n)) = A276087(n), a(a(a(n))) = A328403(n). [2- and 3-fold applications]
a(2n+1) = 2 * a(2n). - Antti Karttunen, Feb 17 2022

Extensions

Name edited and new link-formulas added by Antti Karttunen, Oct 29 2019
Name changed again by Antti Karttunen, Feb 05 2022

A276085 Primorial base log-function: fully additive with a(p) = p#/p, where p# = A034386(p).

Original entry on oeis.org

0, 1, 2, 2, 6, 3, 30, 3, 4, 7, 210, 4, 2310, 31, 8, 4, 30030, 5, 510510, 8, 32, 211, 9699690, 5, 12, 2311, 6, 32, 223092870, 9, 6469693230, 5, 212, 30031, 36, 6, 200560490130, 510511, 2312, 9, 7420738134810, 33, 304250263527210, 212, 10, 9699691, 13082761331670030, 6, 60, 13, 30032, 2312, 614889782588491410, 7, 216, 33, 510512, 223092871, 32589158477190044730, 10
Offset: 1

Views

Author

Antti Karttunen, Aug 21 2016

Keywords

Comments

Completely additive with a(p^e) = e * A002110(A000720(p)-1).
This is a left inverse of A276086 ("primorial base exp-function"), hence the name "primorial base log-function". When the domain is restricted to the terms of A048103, this works also as a right inverse, as A276086(a(A048103(n))) = A048103(n) for all n >= 1. - Antti Karttunen, Apr 24 2022
On average, every third term is a multiple of 4. See A369001. - Antti Karttunen, May 26 2024

Crossrefs

A left inverse of A276086.
Positions of multiples of k in this sequence, for k=2, 3, 4, 5, 8, 27, 3125: A003159, A339746, A369002, A373140, A373138, A377872, A377878.
Cf. A036554 (positions of odd terms), A035263, A096268 (parity of terms).
Cf. A372575 (rgs-transform), A372576 [a(n) mod 360], A373842 [= A003415(a(n))].
Cf. A373145 [= gcd(A003415(n), a(n))], A373361 [= gcd(n, a(n))], A373362 [= gcd(A001414(n), a(n))], A373485 [= gcd(A083345(n), a(n))], A373835 [= gcd(bigomega(n), a(n))], and also A373367 and A373147 [= A003415(n) mod a(n)], A373148 [= a(n) mod A003415(n)].
Other completely additive sequences with primes p mapped to a function of p include: A001222 (with a(p)=1), A001414 (with a(p)=p), A059975 (with a(p)=p-1), A341885 (with a(p)=p*(p+1)/2), A373149 (with a(p)=prevprime(p)), A373158 (with a(p)=p#).
Cf. also A276075 for factorial base and A048675, A054841 for base-2 and base-10 analogs.

Programs

  • Mathematica
    nn = 60; b = MixedRadix[Reverse@ Prime@ Range@ PrimePi[nn + 1]]; Table[FromDigits[#, b] &@ Reverse@ If[n == 1, {0}, Function[k, ReplacePart[Table[0, {PrimePi[k[[-1, 1]]]}], #] &@ Map[PrimePi@ First@ # -> Last@ # &, k]]@ FactorInteger@ n], {n, nn}] (* Version 10.2, or *)
    f[w_List] := Total[Times @@@ Transpose@ {Map[Times @@ # &, Prime@ Range@ Range[0, Length@ w - 1]], Reverse@ w}]; Table[f@ Reverse@ If[n == 1, {0}, Function[k, ReplacePart[Table[0, {PrimePi[k[[-1, 1]]]}], #] &@ Map[PrimePi@ First@ # -> Last@ # &, k]]@ FactorInteger@ n], {n, 60}] (* Michael De Vlieger, Aug 30 2016 *)
  • PARI
    A276085(n) = { my(f = factor(n), pr=1, i=1, s=0); for(k=1, #f~, while(i <= primepi(f[k, 1])-1, pr *= prime(i); i++); s += f[k, 2]*pr); (s); }; \\ Antti Karttunen, Nov 11 2024
    
  • Python
    from sympy import primorial, primepi, factorint
    def a002110(n):
        return 1 if n<1 else primorial(n)
    def a(n):
        f=factorint(n)
        return sum(f[i]*a002110(primepi(i) - 1) for i in f)
    print([a(n) for n in range(1, 101)]) # Indranil Ghosh, Jun 22 2017

Formula

a(1) = 0; for n > 1, a(n) = a(A028234(n)) + (A067029(n) * A002110(A055396(n)-1)).
a(1) = 0, a(n) = (e1*A002110(i1-1) + ... + ez*A002110(iz-1)) when n = prime(i1)^e1 * ... * prime(iz)^ez.
Other identities.
For all n >= 0:
a(A276086(n)) = n.
a(A000040(1+n)) = A002110(n).
a(A002110(1+n)) = A143293(n).
From Antti Karttunen, Apr 24 & Apr 29 2022: (Start)
a(A283477(n)) = A283985(n).
a(A108951(n)) = A346105(n). [The latter has a similar additive formula as this sequence, but instead of primorials, uses their partial sums]
When applied to sequences where a certain subset of the divisors of n has been multiplicatively encoded with the help of A276086, this yields a corresponding number-theoretical sequence, i.e. completes their computation:
a(A319708(n)) = A001065(n) and a(A353564(n)) = A051953(n).
a(A329350(n)) = A069359(n) and a(A329380(n)) = A323599(n).
In the following group, the sum of the rhs-sequences is n [on each row, as say, A328841(n)+A328842(n)=n], because the pointwise product of the corresponding lhs-sequences is A276086:
a(A053669(n)) = A053589(n) and a(A324895(n)) = A276151(n).
a(A328571(n)) = A328841(n) and a(A328572(n)) = A328842(n).
a(A351231(n)) = A351233(n) and a(A327858(n)) = A351234(n).
a(A351251(n)) = A351253(n) and a(A324198(n)) = A351254(n).
The sum or difference of the rhs-sequences is A108951:
a(A344592(n)) = A346092(n) and a(A346091(n)) = A346093(n).
a(A346106(n)) = A346108(n) and a(A346107(n)) = A346109(n).
Here the two sequences are inverse permutations of each other:
a(A328624(n)) = A328625(n) and a(A328627(n)) = A328626(n).
a(A346102(n)) = A328622(n) and a(A346233(n)) = A328623(n).
a(A346101(n)) = A289234(n). [Self-inverse]
Other correspondences:
a(A324350(x,y)) = A324351(x,y).
a(A003961(A276086(n))) = A276154(n). [The primorial base left shift]
a(A276076(n)) = A351576(n). [Sequence reinterpreting factorial base representation as a primorial base representation]
(End)

Extensions

Name amended by Antti Karttunen, Apr 24 2022
Name simplified, the old name moved to the comments - Antti Karttunen, Jun 23 2024

A328624 Twisted variant of A276086 indexed by A328625.

Original entry on oeis.org

1, 2, 3, 18, 9, 6, 5, 10, 75, 450, 1125, 750, 25, 50, 1875, 11250, 45, 30, 125, 250, 15, 90, 5625, 3750, 625, 1250, 375, 2250, 225, 150, 7, 14, 21, 126, 63, 42, 245, 490, 3675, 22050, 55125, 36750, 8575, 17150, 643125, 3858750, 15435, 10290, 300125, 600250, 36015, 216090, 13505625, 9003750, 10504375, 21008750, 6302625, 37815750, 3781575, 2521050, 49, 98
Offset: 0

Views

Author

Antti Karttunen, Oct 23 2019

Keywords

Crossrefs

Programs

  • PARI
    A328624(n) = { my(m=1, p=2, e, g=1); while(n, e = (n%p); m *= (p^((g*e)%p)); g = e+1; n = n\p; p = nextprime(1+p)); (m); };

Formula

a(n) = A276086(A328625(n)).
A001222(a(n)) = A328630(n).

A328626 Inverse permutation to A328625.

Original entry on oeis.org

0, 1, 2, 5, 4, 3, 6, 7, 20, 17, 16, 21, 12, 13, 8, 29, 28, 9, 18, 19, 26, 11, 10, 27, 24, 25, 14, 23, 22, 15, 30, 31, 32, 35, 34, 33, 126, 127, 80, 167, 166, 81, 162, 163, 128, 119, 118, 129, 78, 79, 116, 131, 130, 117, 114, 115, 164, 83, 82, 165, 60, 61, 62, 65, 64, 63, 36, 37, 140, 107, 106, 141, 102, 103, 38, 209, 208, 39, 138, 139, 206, 41, 40
Offset: 0

Views

Author

Antti Karttunen, Oct 25 2019

Keywords

Crossrefs

Cf. A328625 (inverse permutation).
Cf. also A289234, A328623.

Programs

  • PARI
    A002110(n) = prod(i=1,n,prime(i));
    A276085(n) = { my(f = factor(n)); sum(k=1, #f~, f[k, 2]*A002110(primepi(f[k, 1])-1)); };
    A328627(n) = { my(m=1, p=2, d=0); while(n, d = lift(Mod(n,p)/(d+1)); m *= (p^d); n = n\p; p = nextprime(1+p)); (m); };
    A328626(n) = A276085(A328627(n));

Formula

a(n) = A276085(A328627(n)).
For all n, A328620(a(n)) = A328620(n).

A346101 "Inverted variant" of A276086: a(n) = A276086(A289234(n)).

Original entry on oeis.org

1, 2, 3, 6, 9, 18, 5, 10, 15, 30, 45, 90, 125, 250, 375, 750, 1125, 2250, 25, 50, 75, 150, 225, 450, 625, 1250, 1875, 3750, 5625, 11250, 7, 14, 21, 42, 63, 126, 35, 70, 105, 210, 315, 630, 875, 1750, 2625, 5250, 7875, 15750, 175, 350, 525, 1050, 1575, 3150, 4375, 8750, 13125, 26250, 39375, 78750, 2401, 4802, 7203, 14406
Offset: 0

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Author

Antti Karttunen, Jul 10 2021

Keywords

Crossrefs

Programs

  • PARI
    A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
    A289234(n) = { my(pr=1, p=2, v=0); while(n>0, my (d=n%p); if(d>0, v += pr * lift(1/Mod(d, p))); pr *= p; n \= p; p = nextprime(1+p)); return(v); }; \\ From A289234.
    A346101(n) = A276086(A289234(n));
    
  • PARI
    A346101(n) = { my(p=2, m=1); while(n>0, my(d=n%p); if(d>0, m *= p^lift(1/Mod(d, p))); n \= p; p = nextprime(1+p)); return(m); };

Formula

a(n) = A276086(A289234(n)).
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