This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A124920 Location of record values in A080577; also partial sums of A006128 plus 1. 2
 1, 2, 5, 11, 23, 43, 78, 132, 218, 346, 538, 813, 1212, 1768, 2548, 3616, 5079, 7044, 9688, 13186, 17816, 23868, 31767, 41973, 55147, 71998, 93520, 120814, 155359, 198812, 253375, 321510, 406437, 511803, 642265, 803141, 1001155, 1243967 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Vaclav Kotesovec, Table of n, a(n) for n = 1..10000 FORMULA A124920(n) = A124920(n-1)+ A006128(n-1), n>1; a(1) = 1. G.f.: x/(1 - x) + Sum_{i>=1} i*x^(i+1)/(1 - x) * Product_{j=1..i} 1/(1 - x^j). - Ilya Gutkovskiy, Apr 04 2017 a(n) ~ exp(Pi*sqrt(2*n/3)) * (log(6*n) + 2*gamma - 2*log(Pi)) * sqrt(3) / (4*Pi^2), where gamma is the Euler-Mascheroni constant (A001620). - Vaclav Kotesovec, May 19 2018 EXAMPLE A080577 begins 1 2 11 3 21 111 4 31 22 211 1111 5 41 32 311 221 2111 11111 6 51 42 411 33 321 3111 222 2211 21111 111111 therefore A124920 begins 1 2 5 11 23 ... MAPLE A008284 := proc(n, k) if n >= 1 and n = k or k = 1 then 1 elif k > n then 0 else add( A008284(n-k, i), i=1..k) ; fi ; end: A006128 := proc(n) add( k*A008284(n, k), k=1..n) ; end: a := 1 : printf("%d, ", a) ; for n from 2 to 80 do a := a + A006128(n-1) : printf("%d, ", a) ; od : # R. J. Mathar, Jan 13 2007 CROSSREFS Cf. A000041, A006128, A080577. Sequence in context: A186265 A225947 A281969 * A064934 A227637 A171985 Adjacent sequences:  A124917 A124918 A124919 * A124921 A124922 A124923 KEYWORD easy,nonn AUTHOR Alford Arnold, Nov 13 2006 EXTENSIONS More terms from R. J. Mathar, Jan 13 2007 Clarification of name from Ilya Gutkovskiy, Apr 04 2017 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 March 20 15:43 EDT 2019. Contains 321345 sequences. (Running on oeis4.)