A037287 Replace 2n+1 with concatenation of its divisors >1.

0, 3, 5, 7, 39, 11, 13, 3515, 17, 19, 3721, 23, 525, 3927, 29, 31, 31133, 5735, 37, 31339, 41, 43, 3591545, 47, 749, 31751, 53, 51155, 31957, 59, 61, 3792163, 51365, 67, 32369, 71, 73, 35152575, 71177, 79, 392781, 83, 51785, 32987, 89, 71391, 33193

Offset

0,2

Links

Harvey P. Dale, Table of n, a(n) for n = 0..1000

Example

Divisors of 15 are 1,3,5,15, so a(7)=3515

Mathematica

Join[{0}, Table[FromDigits[Flatten[IntegerDigits/@Rest[Divisors[2n+1]]]], {n, 50}]] (* Harvey P. Dale, Aug 01 2019 *)

Crossrefs

Sequence in context: A182373 A087363 A234569 * A163797 A339900 A130536

Adjacent sequences: A037284 A037285 A037286 * A037288 A037289 A037290

Keyword

nonn,base,easy

Author

N. J. A. Sloane

Extensions

More terms from Erich Friedman

Status

approved