This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A249622 a(n) = number of ways to express A117048(n) as the sum of two positive triangular numbers. 2
 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 3, 2, 1, 1, 3, 1, 2, 1, 1, 2, 1, 3, 1, 2, 1, 2, 1, 1, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 4, 1, 3, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 2, 4, 1, 1, 1, 3, 1, 1, 2, 1, 2, 2, 1, 1, 2, 1, 1, 3, 1, 2, 1, 2, 1, 1, 6, 2, 1, 1, 1, 1 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,6 LINKS Zak Seidov, Table of n, a(n) for n = 1..10000 EXAMPLE a(6) = 2 because A117048(6) = 31 and 31 = 3 + 28 = 10 + 21 (first case of two-way expression). a(22) = 3 because A117048(22) = 181 and 181 = A000217(i) + A000217(k), for {i,k} = {{4, 18}, {7, 17}, {9, 16}} (first case of three-way expression): 181 = 10 + 171 = 28 + 153 = 45 + 136. CROSSREFS Cf. A000040, A000217, A002383. Sequence in context: A307609 A043287 A212177 * A287656 A043286 A172098 Adjacent sequences:  A249619 A249620 A249621 * A249623 A249624 A249625 KEYWORD nonn AUTHOR Zak Seidov, Nov 03 2014 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 May 25 03:14 EDT 2019. Contains 323539 sequences. (Running on oeis4.)