A065998 Concatenate n and number of divisors of n.

11, 22, 32, 43, 52, 64, 72, 84, 93, 104, 112, 126, 132, 144, 154, 165, 172, 186, 192, 206, 214, 224, 232, 248, 253, 264, 274, 286, 292, 308, 312, 326, 334, 344, 354, 369, 372, 384, 394, 408, 412, 428, 432, 446, 456, 464, 472, 4810, 493, 506, 514, 526, 532

Offset

1,1

Links

Harry J. Smith, Table of n, a(n) for n=1..1000

Mathematica

cnd[n_]:=Module[{ds=DivisorSigma[0, n]}, n*10^IntegerLength[ds]+ds]; Array[ cnd, 60] (* Harvey P. Dale, Aug 22 2019 *)

Prog

(PARI) digitsIn(x)= { local(d); if (x==0, return(1)); d=1 + log(x)\log(10); if (10^d == x, d++, if (10^(d-1) > x, d--)); return(d) }
Concat(a, b)= { return(a*10^digitsIn(b) + b) }
{ for (n=1, 1000, a=Concat(n, numdiv(n)); write("b065998.txt", n, " ", a) ) } \\ Harry J. Smith, Nov 06 2009
(PARI) a(n) = fromdigits(concat(digits(n), digits(numdiv(n)))); \\ Michel Marcus, Apr 02 2017

Crossrefs

Cf. A000005.

Sequence in context: A374365 A178897 A013576 * A364275 A351877 A073729

Adjacent sequences: A065995 A065996 A065997 * A065999 A066000 A066001

Keyword

nonn,base

Author

Jeff Burch, Feb 28 2001

Status

approved