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 11-20 of 20 results.

A059691 Carryless product 12 X n base 10.

Original entry on oeis.org

0, 12, 24, 36, 48, 50, 62, 74, 86, 98, 120, 132, 144, 156, 168, 170, 182, 194, 106, 118, 240, 252, 264, 276, 288, 290, 202, 214, 226, 238, 360, 372, 384, 396, 308, 310, 322, 334, 346, 358, 480, 492, 404, 416, 428, 430, 442, 454, 466, 478, 500, 512, 524, 536
Offset: 0

Views

Author

Henry Bottomley, Feb 19 2001

Keywords

Examples

			a(97)=954 since we have 12 X 97 = carryless sum of 900, 80, 70 and 4 = 954
		

Crossrefs

Cf. A001477 for carryless 1 X n, A004520 for carryless 2 X n base 10, A055120 for carryless 9 X n, A008592 for carryless 10 X n.

A059734 Carryless 11^n base 10; a(n) is carryless sum of 10*a(n-1) and a(n-1).

Original entry on oeis.org

1, 11, 121, 1331, 14641, 150051, 1650561, 17155171, 188606881, 1964664691, 10500200501, 115502205511, 1260524250621, 13865766756831, 141412323214141, 1555535555355551, 16000880008800061, 176008680086800671
Offset: 0

Views

Author

Henry Bottomley, Feb 20 2001

Keywords

Comments

Subsequence of A002113. - Chai Wah Wu, Jul 30 2025

Examples

			a(7)=17155171 since a(6)=1650561 and digits of a(7) are sum mod 10 of 1, 6+1=7, 5+6=1, 0+5=5, 5+0=5, 6+5=1, 1+6=7 and 1.
		

Crossrefs

Programs

  • Mathematica
    Table[Sum[Mod[Binomial[n, m], 10]*10^m, {m, 0, n}], {n, 0, 30}] (* Roger L. Bagula and Gary W. Adamson, Sep 14 2008 *)
  • PARI
    a(n) = fromdigits(Vec(Pol(digits(11))^n)%10); \\ Seiichi Manyama, Mar 10 2023
    
  • Python
    from math import comb, prod
    from sympy.ntheory.modular import crt
    from gmpy2 import digits
    def A059734(n):
        k, l = 0, len(s:=digits(n,5))
        for m in range(n+1):
            t = digits(m,5).zfill(l)
            k = 10*k+crt([5,2],[prod(comb(int(s[i]),int(t[i]))%5 for i in range(l))%5,int(not ~n & m)])[0]
        return k # Chai Wah Wu, Jul 30 2025

Formula

a(n)=Sum[Mod[Binomial[n, m], 10]*10^m, {m, 0, n}]. - Roger L. Bagula and Gary W. Adamson, Sep 14 2008

A169903 Primitive primes in carryless arithmetic mod 10.

Original entry on oeis.org

21, 23, 25, 27, 29, 51, 56, 201, 209, 227, 229, 241, 243, 261, 263, 287, 289, 551, 2023, 2027, 2043, 2047, 2061, 2069, 2081, 2089, 2207, 2209, 2221, 2223, 2263, 2267, 2281, 2287, 2401, 2407, 2421, 2423, 2441, 2449, 2483, 2489, 2603, 2609
Offset: 1

Views

Author

Keywords

Comments

Define the units in carryless arithmetic mod 10 to be the numbers 1, 3, 7 and 9 (these divide any number). A prime is a number N, not a unit, whose only factorizations are of the form N = u * M, where u is a unit.
A prime is primitive if it is not the carryless product of a smaller prime and a unit.
A subsequence of A169887.

Crossrefs

A359697 Triangle T(n,k), n >= 1, 1 <= k <= n, read by rows, where T(n,k) is carryless product n X k base 10.

Original entry on oeis.org

1, 2, 4, 3, 6, 9, 4, 8, 2, 6, 5, 0, 5, 0, 5, 6, 2, 8, 4, 0, 6, 7, 4, 1, 8, 5, 2, 9, 8, 6, 4, 2, 0, 8, 6, 4, 9, 8, 7, 6, 5, 4, 3, 2, 1, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 11, 22, 33, 44, 55, 66, 77, 88, 99, 110, 121, 12, 24, 36, 48, 50, 62, 74, 86, 98, 120, 132, 144
Offset: 1

Views

Author

Seiichi Manyama, Mar 08 2023

Keywords

Examples

			Triangle begins:
   1;
   2,  4;
   3,  6,  9;
   4,  8,  2,  6;
   5,  0,  5,  0,  5;
   6,  2,  8,  4,  0,  6;
   7,  4,  1,  8,  5,  2,  9;
   8,  6,  4,  2,  0,  8,  6,  4;
   9,  8,  7,  6,  5,  4,  3,  2,  1;
  10, 20, 30, 40, 50, 60, 70, 80, 90, 100;
  11, 22, 33, 44, 55, 66, 77, 88, 99, 110, 121;
  12, 24, 36, 48, 50, 62, 74, 86, 98, 120, 132, 144;
		

Crossrefs

T(n,n) gives A059729.
Cf. A001477 for carryless 1 X n, A004520 for carryless 2 X n base 10, A055120 for carryless 9 X n, A008592 for carryless 10 X n, A059691 for carryless 12 X n.

Programs

  • PARI
    T(n, k) = fromdigits(Vec(Pol(digits(n))*Pol(digits(k)))%10);

A059626 Generalized nim sum n + n + n in base 10; carryless multiplication 3 X n base 10.

Original entry on oeis.org

0, 3, 6, 9, 2, 5, 8, 1, 4, 7, 30, 33, 36, 39, 32, 35, 38, 31, 34, 37, 60, 63, 66, 69, 62, 65, 68, 61, 64, 67, 90, 93, 96, 99, 92, 95, 98, 91, 94, 97, 20, 23, 26, 29, 22, 25, 28, 21, 24, 27, 50, 53, 56, 59, 52, 55, 58, 51, 54, 57, 80, 83, 86, 89, 82, 85, 88, 81, 84, 87, 10, 13
Offset: 0

Views

Author

Henry Bottomley, Feb 19 2001

Keywords

Crossrefs

Cf. A001477 for carryless 1 X n, A004520 for carryless 2 X 10 base 10, A008592 for carryless 10 X n.

A059629 Carryless multiplication 6 X n base 10.

Original entry on oeis.org

0, 6, 2, 8, 4, 0, 6, 2, 8, 4, 60, 66, 62, 68, 64, 60, 66, 62, 68, 64, 20, 26, 22, 28, 24, 20, 26, 22, 28, 24, 80, 86, 82, 88, 84, 80, 86, 82, 88, 84, 40, 46, 42, 48, 44, 40, 46, 42, 48, 44, 0, 6, 2, 8, 4, 0, 6, 2, 8, 4, 60, 66, 62, 68, 64, 60, 66, 62, 68, 64, 20, 26, 22, 28, 24
Offset: 0

Views

Author

Henry Bottomley, Feb 19 2001

Keywords

Crossrefs

Cf. A001477 for carryless 1 X n, A004520 for carryless 2 X 10 base 10, A008592 for carryless 10 X n.

A059631 Carryless multiplication 8 X n base 10.

Original entry on oeis.org

0, 8, 6, 4, 2, 0, 8, 6, 4, 2, 80, 88, 86, 84, 82, 80, 88, 86, 84, 82, 60, 68, 66, 64, 62, 60, 68, 66, 64, 62, 40, 48, 46, 44, 42, 40, 48, 46, 44, 42, 20, 28, 26, 24, 22, 20, 28, 26, 24, 22, 0, 8, 6, 4, 2, 0, 8, 6, 4, 2, 80, 88, 86, 84, 82, 80, 88, 86, 84, 82, 60, 68, 66, 64, 62
Offset: 0

Views

Author

Henry Bottomley, Feb 19 2001

Keywords

Crossrefs

Cf. A001477 for carryless 1 X n, A004520 for carryless 2 X 10 base 10, A008592 for carryless 10 X n.

A059627 Generalized nim sum n + n + n + n in base 10; carryless multiplication 4 X n base 10.

Original entry on oeis.org

0, 4, 8, 2, 6, 0, 4, 8, 2, 6, 40, 44, 48, 42, 46, 40, 44, 48, 42, 46, 80, 84, 88, 82, 86, 80, 84, 88, 82, 86, 20, 24, 28, 22, 26, 20, 24, 28, 22, 26, 60, 64, 68, 62, 66, 60, 64, 68, 62, 66, 0, 4, 8, 2, 6, 0, 4, 8, 2, 6, 40, 44, 48, 42, 46, 40, 44, 48, 42, 46, 80, 84, 88, 82, 86
Offset: 0

Views

Author

Henry Bottomley, Feb 19 2001

Keywords

Crossrefs

Cf. A001477 for carryless 1 X n, A004520 for carryless 2 X 10 base 10, A008592 for carryless 10 X n.

A059628 Carryless multiplication 5 X n base 10.

Original entry on oeis.org

0, 5, 0, 5, 0, 5, 0, 5, 0, 5, 50, 55, 50, 55, 50, 55, 50, 55, 50, 55, 0, 5, 0, 5, 0, 5, 0, 5, 0, 5, 50, 55, 50, 55, 50, 55, 50, 55, 50, 55, 0, 5, 0, 5, 0, 5, 0, 5, 0, 5, 50, 55, 50, 55, 50, 55, 50, 55, 50, 55, 0, 5, 0, 5, 0, 5, 0, 5, 0, 5, 50, 55, 50, 55, 50, 55, 50, 55, 50, 55, 0, 5, 0, 5
Offset: 0

Views

Author

Henry Bottomley, Feb 19 2001

Keywords

Crossrefs

Cf. A001477 for carryless 1 X n, A004520 for carryless 2 X 10 base 10, A008592 for carryless 10 X n.

A059630 Carryless multiplication 7 X n base 10.

Original entry on oeis.org

0, 7, 4, 1, 8, 5, 2, 9, 6, 3, 70, 77, 74, 71, 78, 75, 72, 79, 76, 73, 40, 47, 44, 41, 48, 45, 42, 49, 46, 43, 10, 17, 14, 11, 18, 15, 12, 19, 16, 13, 80, 87, 84, 81, 88, 85, 82, 89, 86, 83, 50, 57, 54, 51, 58, 55, 52, 59, 56, 53, 20, 27, 24, 21, 28, 25, 22, 29, 26, 23, 90, 97
Offset: 0

Views

Author

Henry Bottomley, Feb 19 2001

Keywords

Crossrefs

Cf. A001477 for carryless 1 X n, A004520 for carryless 2 X 10 base 10, A008592 for carryless 10 X n.
Previous Showing 11-20 of 20 results.