A193715 Positions of triangular numbers (A000217) in the union of squares and triangular numbers (A005214).

1, 2, 4, 6, 7, 9, 11, 12, 13, 15, 17, 18, 20, 22, 23, 25, 27, 29, 30, 32, 34, 35, 37, 39, 41, 42, 44, 46, 47, 49, 51, 52, 54, 56, 58, 59, 61, 63, 64, 66, 68, 70, 71, 73, 75, 76, 78, 80, 81, 82, 84, 86, 87, 89, 91, 92, 94, 96, 98, 99, 101, 103, 104, 106, 108

Offset

1,2

Comments

A010054(A005214(a(n))) = 1.

Links

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Prog

(Haskell)
import Data.List (elemIndex)
import Data.Maybe (fromJust)
a193715 n = a193715_list !! (n-1)
a193715_list =
   map ((+ 1) . fromJust . (`elemIndex` a005214_list)) $ tail a000217_list

Crossrefs

Cf. A193714.

Sequence in context: A052056 A356754 A187974 * A320474 A051533 A186151

Adjacent sequences: A193712 A193713 A193714 * A193716 A193717 A193718

Keyword

nonn

Author

Reinhard Zumkeller, Aug 03 2011

Status

approved