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.

Previous Showing 11-16 of 16 results.

A255415 Row 5 of Ludic array A255127.

Original entry on oeis.org

11, 55, 103, 151, 203, 251, 299, 343, 391, 443, 491, 539, 587, 631, 683, 731, 779, 827, 877, 923, 971, 1019, 1067, 1117, 1165, 1211, 1259, 1307, 1357, 1405, 1453, 1499, 1547, 1597, 1645, 1693, 1741, 1787, 1837, 1885, 1933, 1981, 2033, 2077, 2125, 2173, 2221, 2273, 2321, 2365, 2413, 2461, 2513, 2561, 2609, 2653, 2701, 2753, 2801, 2849, 2897, 2941, 2993, 3041
Offset: 1

Views

Author

Antti Karttunen, Feb 22 2015

Keywords

Comments

First differences are periodic with period length 48, cf. formulas. - M. F. Hasler, Nov 17 2024

Crossrefs

Row 5 of A255127. See A255414 for row 4 and A255416 for row 6.

Programs

  • PARI
    L255415=[n*337\14*2+7|n<-[0..47]]+digits(54129937554927109457534, 3)*2
    apply( A255415(n)=n--\48*2310+L255415[n%48+1], [1..66]) \\ M. F. Hasler, Nov 10 2024
  • Scheme
    (define (A255415 n) (A255127bi 5 n)) ;; Code for A255127bi given in A255127.
    

Formula

a(n) = A255407(A084969(n)).
a(n) = a(n-48) + 2310 = a((n-1)%48 + 1) + [(n-1)/48]*2310, where % = mod = remainder operator, and [.] = floor. - M. F. Hasler, Nov 10 2024

A260435 Permutation mapping from Lucky sieve to Ludic sieve: a(1) = 1, for n > 1: a(n) = A255127(A260438(n), A260439(n)).

Original entry on oeis.org

1, 2, 3, 4, 9, 6, 5, 8, 7, 10, 15, 12, 11, 14, 13, 16, 21, 18, 19, 20, 17, 22, 27, 24, 23, 26, 31, 28, 33, 30, 25, 32, 29, 34, 39, 36, 37, 38, 35, 40, 45, 42, 41, 44, 55, 46, 51, 48, 43, 50, 47, 52, 57, 54, 73, 56, 59, 58, 63, 60, 49, 62, 53, 64, 69, 66, 61, 68, 67, 70, 75, 72, 71, 74, 77, 76, 81, 78, 83, 80, 65, 82, 87, 84, 101, 86, 89, 88
Offset: 1

Views

Author

Antti Karttunen, Jul 30 2015

Keywords

Comments

a(n) tells which number in array A255127 (constructed from Ludic sieve) is at the same position where n is in array A255551 (constructed from Lucky sieve). This permutation fixes all even numbers because both arrays have A005843 as their topmost row.

Crossrefs

Inverse: A260436.
Similar or related permutations: A255407, A255552, A255554, A249817, A249818, A260741 (a more recursed variant).

Programs

Formula

Other identities. For all n >= 1:
a(A000959(n+1)) = A003309(n+2). [Maps Lucky numbers to odd Ludic numbers.]
a(2n) = 2n.
As a composition of related permutations:
a(n) = A255127(A255552(n)).
a(n) = A255407(A255554(n)).

A269355 Permutation of natural numbers: a(n) = A269380(A250469(n)).

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 23, 10, 11, 12, 13, 14, 15, 16, 9, 18, 17, 20, 31, 22, 25, 24, 21, 26, 27, 28, 19, 30, 29, 32, 49, 34, 71, 36, 37, 38, 39, 40, 41, 42, 43, 44, 107, 46, 47, 48, 119, 50, 51, 52, 35, 54, 89, 56, 101, 58, 53, 60, 61, 62, 63, 64, 115, 66, 67, 68, 173, 70, 55, 72, 33, 74, 75, 76, 131, 78, 77, 80, 167
Offset: 1

Views

Author

Antti Karttunen, Mar 03 2016

Keywords

Examples

			For n=9 we first find what number is below 9 in square array A083221, which is 25, then we find what number is above 25 in square array A255127, which is 23, thus a(9) = 23.
		

Crossrefs

Inverse: A269356.
Cf. also arrays A083221 & A255127.
More recursed variant: A269357. Cf. also permutations A266645, A255407, A269171.

Programs

Formula

a(n) = A269380(A250469(n)).
Other identities. For all n >= 1:
a(2n) = 2n. [Fixes the even numbers.]

A255410 Main diagonal of Ludic array A255127 (and A255129): a(n) = A255127(n,n).

Original entry on oeis.org

2, 9, 35, 85, 203, 325, 547, 911, 1181, 1591, 2347, 2923, 3421, 4151, 5161, 6461, 7693, 8785, 10237, 11789, 13469, 14621, 16523, 19225, 21775, 23669, 25237, 27715, 29891, 34073, 36977, 40487, 43151, 48091, 50429, 53407, 55843, 61541, 68797, 71603, 77279, 80291, 84091, 88771, 91997, 96119, 101927, 108833, 115031, 123187
Offset: 1

Views

Author

Antti Karttunen, Feb 22 2015

Keywords

Crossrefs

Programs

Formula

a(n) = A255127(n,n).
a(n) = A255407(A083141(n)).

A255416 Row 6 of Ludic array A255127.

Original entry on oeis.org

13, 73, 133, 197, 263, 325, 385, 449, 511, 571, 641, 701, 761, 823, 887, 947, 1013, 1075, 1139, 1199, 1261, 1327, 1387, 1447, 1513, 1573, 1637, 1703, 1763, 1825, 1889, 1951, 2011, 2071, 2141, 2201, 2261, 2327, 2387, 2453, 2515, 2575, 2639, 2699, 2767, 2827, 2887, 2953, 3013, 3073, 3143, 3203, 3265, 3325, 3389, 3451, 3511, 3581, 3641, 3701
Offset: 1

Views

Author

Antti Karttunen, Feb 22 2015

Keywords

Crossrefs

Row 6 of A255127. See A255415 for row 5 and A255417 for row 7.

Programs

  • PARI
    my(L=[x+2^(x%2)|x<-[1..10^4]*3], m(n,k)=2^(n\/k*k)\(2^k-1)); for(i=3, 5, L=vecextract(L, 2^#L-m(#L, L[1])-1)); L255416=vecextract(L, m(#L, L[1]));
    A255416(n)=n--\480*30030+L255416[n%480+1] \\ M. F. Hasler, Nov 17 2024
    
  • Python
    def A255416(n):
        try: n-=1; return A255416.L[n]
        except IndexError: return n//480*30030 + A255416.L[n%480]
        except AttributeError: L = [3*x+5-(x&1) for x in range(10**4)]
        for k in L[:3]: L = [x for i,x in enumerate(L) if i%k]
        A255416.L = L[::13]; return n//480*30030 + A255416.L[n%480]
    # M. F. Hasler, Nov 17 2024
  • Scheme
    (define (A255416 n) (A255127bi 6 n)) ;; Code for A255127bi given in A255127.
    

Formula

a(n) = A255407(A084970(n)).
a(n) = a(n-480) + 30030 = 30030*floor((n-1)/480) + a((n-1)%480 + 1), where % is the modulo or remainder operator. - M. F. Hasler, Nov 10 2024 and Nov 17 2024

A269395 Permutation of natural numbers: a(n) = A269171(A269393(n)) = A269171(A269171(3*n)/3).

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 23, 20, 21, 22, 25, 24, 19, 26, 27, 28, 29, 30, 37, 32, 33, 34, 35, 36, 45, 46, 39, 40, 43, 42, 47, 44, 31, 50, 53, 48, 41, 38, 51, 52, 61, 54, 49, 56, 57, 58, 67, 60, 89, 74, 63, 64, 65, 66, 77, 68, 69, 70, 83, 72, 81, 90, 85, 92, 59, 78, 91, 80, 79
Offset: 1

Views

Author

Antti Karttunen, Mar 03 2016

Keywords

Comments

Composition of A269171 with a permutation of natural numbers obtained from its trisection.

Crossrefs

Inverse: A269396.
Cf. A269393.
Differs from A255407 and A269171 for the first time at n=37, which here a(37)=45, instead of 41.

Programs

Formula

a(n) = A269171(A269393(n)) = A269171(A269171(3*n)/3).
Previous Showing 11-16 of 16 results.