The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A162962 a(n) = 5*a(n-2) for n > 2; a(1) = 1, a(2) = 5. 1
 1, 5, 5, 25, 25, 125, 125, 625, 625, 3125, 3125, 15625, 15625, 78125, 78125, 390625, 390625, 1953125, 1953125, 9765625, 9765625, 48828125, 48828125, 244140625, 244140625, 1220703125, 1220703125, 6103515625, 6103515625, 30517578125 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Apparently a(n) = A074872(n+1), a(n) = A056451(n-1) for n > 1. Binomial transform is A084057 without initial 1, second binomial transform is A048876, third binomial transform is A082762, fourth binomial transform is A162769, fifth binomial transform is A093145 without initial 0. LINKS Index entries for linear recurrences with constant coefficients, signature (0,5). FORMULA a(n) = 5^((1/4)*(2*n-1+(-1)^n)). G.f.: x*(1+5*x)/(1-5*x^2). PROG (MAGMA) [ n le 2 select 4*n-3 else 5*Self(n-2): n in [1..30] ]; CROSSREFS Cf. A000351 (powers of 5), A074872 (powers of 5 repeated), A056451 (5^floor((n+1)/2)), A084057, A048876, A082762, A162769, A093145. Sequence in context: A071340 A056451 A074872 * A170834 A154630 A245520 Adjacent sequences:  A162959 A162960 A162961 * A162963 A162964 A162965 KEYWORD nonn,easy AUTHOR Klaus Brockhaus, Jul 19 2009 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified September 21 19:57 EDT 2020. Contains 337273 sequences. (Running on oeis4.)