A128703 Numbers of the form 5^k*p, where 1 <= k <= 5 and p is a prime different from 5.

10, 15, 35, 50, 55, 65, 75, 85, 95, 115, 145, 155, 175, 185, 205, 215, 235, 250, 265, 275, 295, 305, 325, 335, 355, 365, 375, 395, 415, 425, 445, 475, 485, 505, 515, 535, 545, 565, 575, 635, 655, 685, 695, 725, 745, 755, 775, 785, 815, 835, 865, 875, 895, 905

Offset

1,1

Comments

Auxiliary sequence for A128704 which gives the number of groups of order a(n).

Links

Klaus Brockhaus, Table of n, a(n) for n=1..10000

Example

375 = 5^3*3 is a term.

Mathematica

With[{upto=1000}, Select[Union[Flatten[5^Range[5] #&/@Drop[Prime[ Range[ PrimePi[ Ceiling[upto/5]]]], {3}]]], #<=upto&]] (* Harvey P. Dale, Jul 27 2011 *)

Prog

(Magma) [ n: n in [1..910] | #t eq 2 and ((t[1, 1] lt 5 and t[1, 2] eq 1 and t[2, 1] eq 5 and t[2, 2] le 5) or (t[1, 1] eq 5 and t[1, 2] le 5 and t[2, 2] eq 1)) where t is Factorization(n) ];

Crossrefs

Cf. A128704, A000351 (powers of 5).

Sequence in context: A239595 A037379 A055049 * A276914 A078818 A194267

Adjacent sequences: A128700 A128701 A128702 * A128704 A128705 A128706

Keyword

nonn

Author

Klaus Brockhaus, Mar 26 2007

Status

approved