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 1-3 of 3 results.

A257901 Pandigital numbers reordered so that the numbers A050278(n)/5^k, where 5^k||A050278(n), are in nondecreasing order.

Original entry on oeis.org

1304296875, 1342968750, 1437890625, 1824609375, 9123046875, 1923046875, 3104296875, 3142968750, 3649218750, 4137890625, 4862109375, 1034296875, 1269843750, 6349218750, 1284609375, 1293046875, 1347890625, 1432968750, 8124609375, 1629843750, 8462109375
Offset: 1

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If two such numbers A050278(n_1)/5^k_1 and A050278(n_2)/5^k_2 are equal, then A050278(n_1) appears earlier than A050278(n_2) iff A050278(n_1)<A050278(n_2). For example, a(4)/5^8=a(5)/5^9=4671.
There are 46080 such pairs.

Crossrefs

Programs

  • Python
    from itertools import permutations
    l = []
    for d in permutations('0123456789', 10):
        if d[0] != '0':
            d2 = int(''.join(d))
            d = d2
            r = d2 % 5
            while not r:
                d2, r = divmod(d2,5)
            l.append((d2,d))
    l.sort()
    A257901_list = [b for a,b in l] # Chai Wah Wu, May 24 2015

Formula

min(A050278(n)/5^k) = 1304296875/5^8 = 3339.

A257913 Pandigital numbers reordered so that the numbers A050278(n)/(2^k*3^m), where 2^k||A050278(n) and 3^m||A050278(n), appear in nondecreasing order.

Original entry on oeis.org

2845310976, 1379524608, 1745960832, 6398410752, 3076521984, 5892341760, 2305179648, 3718250496, 1578369024, 9145036728, 5392687104, 1356709824, 1607952384, 3215904768, 1485029376, 5638470912, 5619843072, 6185973240, 5234098176, 7246198035, 1072963584
Offset: 1

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Comments

If two such numbers A050278(n_1)/(2^k_1*3^m_1) and A050278(n_2)/(2^k_2*3^m_2) are equal, then A050278(n_1) appears earlier than A050278(n_2) iff A050278(n_1)<A050278(n_2). For example, a(2)/(2^13*3^7)=a(3)/(2^7*3^11)= 77. There are 210189 such pairs.
Note that, a(1) = 2845310976 means that min(A050278(n)/(2^k*3^m)) = 2845310976/(2^19*3^4) = 67.

Crossrefs

A257914 Pandigital numbers reordered so that the numbers A050278(n)/(2^k*5^m), where 2^k||A050278(n) and 5^m||A050278(n), appear in nondecreasing order.

Original entry on oeis.org

3076521984, 1342968750, 3718250496, 6398410752, 1304296875, 1437890625, 3142968750, 1824609375, 3649218750, 9123046875, 1542389760, 1923046875, 1683947520, 1384906752, 2769813504, 2845310976, 1578369024, 3104296875, 1269843750, 6349218750, 1074659328
Offset: 1

Views

Author

Keywords

Comments

If two such numbers A050278(n_1)/(2^k_1*5^m_1) and A050278(n_2)/(2^k_2*5^m_2) are equal, then A050278(n_1) appears earlier than A050278(n_2) iff A050278(n_1)<A050278(n_2). For example, a(8)/(2^0*5^8)=a(9)/(2^1*5^8)= 4671. There are 234710 such pairs.
Note that, a(1) = 3076521984 means that min(A050278(n)/(2^k*5^m)) = 3076521984/(2^21*5^0) = 1467.

Crossrefs

Showing 1-3 of 3 results.