A062331 a(n) is the product of the sum and the product of the digits of n (0 is not to be considered a factor in the product).

1, 4, 9, 16, 25, 36, 49, 64, 81, 1, 2, 6, 12, 20, 30, 42, 56, 72, 90, 4, 6, 16, 30, 48, 70, 96, 126, 160, 198, 9, 12, 30, 54, 84, 120, 162, 210, 264, 324, 16, 20, 48, 84, 128, 180, 240, 308, 384, 468, 25, 30, 70, 120, 180, 250, 330, 420, 520, 630, 36, 42, 96, 162, 240, 330

Offset

1,2

Links

Alois P. Heinz, Table of n, a(n) for n = 1..10000 (first 1000 terms from Harry J. Smith)

Example

a(49) = (4+9)*(4*9) = 13*36 = 458.

Maple

a:= n-> (l-> add(i, i=l)*mul(`if`(i=0, 1, i), i=l))(convert(n, base, 10)):
seq(a(n), n=1..100);  # Alois P. Heinz, Jun 29 2018

Mathematica

psd[n_]:=Module[{idnx0=Select[IntegerDigits[n], #>0&]}, Times@@idnx0  Total[idnx0]]
psd/@Range[90]  (* Harvey P. Dale, Feb 24 2011 *)
Array[Times @@ DeleteCases[#, 0]*Total@ # &@ IntegerDigits[#] &, 65] (* Michael De Vlieger, Jun 29 2018 *)

Prog

(PARI) SumD(x)= { s=0; while (x>9, s+=x-10*(x\10); x\=10); return(s + x) } ProdNzD(x)= { p=1; while (x>9, d=x-10*(x\10); if (d, p*=d); x\=10); return(p*x) } { for (n=1, 1000, write("b062331.txt", n, " ", SumD(n)*ProdNzD(n)) ) } \\ Harry J. Smith, Aug 05 2009

Crossrefs

Cf. A007953, A051801.

Sequence in context: A352598 A303269 A003132 * A069940 A153211 A118881

Adjacent sequences: A062328 A062329 A062330 * A062332 A062333 A062334

Keyword

nonn,easy,base

Author

Amarnath Murthy, Jun 21 2001

Extensions

More terms from Larry Reeves (larryr(AT)acm.org), Jun 22 2001

Status

approved