A025624 -id:A025624 - cp's OEIS frontend

A108201 Numbers of the form (5^i)*(12^j), with i, j >= 0.

1, 5, 12, 25, 60, 125, 144, 300, 625, 720, 1500, 1728, 3125, 3600, 7500, 8640, 15625, 18000, 20736, 37500, 43200, 78125, 90000, 103680, 187500, 216000, 248832, 390625, 450000, 518400, 937500, 1080000, 1244160, 1953125, 2250000, 2592000

Offset: 1

Douglas Winston (douglas.winston(AT)srupc.com), Jun 15 2005

Amiram Eldar, Table of n, a(n) for n = 1..10000

Cf. A025622, A003595, A025623, A025624, A025625, A003598, A107466, A064476.

Take[Union[5^First[#] 12^Last[#]&/@Tuples[Range[0,20],2]],50] (* Harvey P. Dale, Mar 23 2012 *)

Sum_{n>=1} 1/a(n) = 15/11. - Amiram Eldar, Mar 29 2025

A025654 Exponent of 5 (value of i) in n-th number of form 5^i*9^j.

Original entry on oeis.org

0, 1, 0, 2, 1, 0, 3, 2, 1, 4, 0, 3, 2, 5, 1, 4, 0, 3, 6, 2, 5, 1, 4, 0, 7, 3, 6, 2, 5, 1, 8, 4, 0, 7, 3, 6, 2, 9, 5, 1, 8, 4, 0, 7, 3, 10, 6, 2, 9, 5, 1, 8, 4, 0, 11, 7, 3, 10, 6, 2, 9, 5, 1, 12, 8, 4, 0, 11, 7, 3, 10, 6, 2, 13, 9, 5, 1, 12, 8, 4, 0, 11, 7, 3, 14, 10, 6, 2, 13, 9, 5, 1, 12, 8, 4, 15, 0, 11, 7, 3

Offset: 1

David W. Wilson

nonn

Cf. A025624.

A025679 Exponent of 9 (value of j) in n-th number of form 5^i*9^j.

Original entry on oeis.org

0, 0, 1, 0, 1, 2, 0, 1, 2, 0, 3, 1, 2, 0, 3, 1, 4, 2, 0, 3, 1, 4, 2, 5, 0, 3, 1, 4, 2, 5, 0, 3, 6, 1, 4, 2, 5, 0, 3, 6, 1, 4, 7, 2, 5, 0, 3, 6, 1, 4, 7, 2, 5, 8, 0, 3, 6, 1, 4, 7, 2, 5, 8, 0, 3, 6, 9, 1, 4, 7, 2, 5, 8, 0, 3, 6, 9, 1, 4, 7, 10, 2, 5, 8, 0, 3, 6, 9, 1, 4, 7, 10, 2, 5, 8, 0, 11, 3, 6, 9, 1, 4, 7, 10, 2, 5

Offset: 1

David W. Wilson

nonn

Cf. A025624.

cp's OEIS Frontend

A108201 Numbers of the form (5^i)*(12^j), with i, j >= 0.

Views

Author

Keywords

Links

Crossrefs

Programs

Mathematica

Formula

A025654 Exponent of 5 (value of i) in n-th number of form 5^i*9^j.

Views

Author

Keywords

Crossrefs

A025679 Exponent of 9 (value of j) in n-th number of form 5^i*9^j.

Views

Author

Keywords

Crossrefs