The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A267320 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A267320

Smallest m such that A267238(m) = n.
(history; published version)

#6 by N. J. A. Sloane at Sun Feb 21 19:51:32 EST 2016

STATUS

proposed

approved

#5 by Michel Marcus at Wed Jan 13 02:49:55 EST 2016

STATUS

editing

proposed

#4 by Michel Marcus at Wed Jan 13 02:48:31 EST 2016

PROG

(PARI) strd(n) = {my(d = digits(n)); sum(k=1, #d, d[k]*(d[k]+1)/2); }

a(n) = {m = 0; while(strd(m) != n, m++); m; } \\ Michel Marcus, Jan 13 2016

STATUS

proposed

editing

#3 by Ivan N. Ianakiev at Wed Jan 13 02:39:07 EST 2016

STATUS

editing

proposed

#2 by Ivan N. Ianakiev at Wed Jan 13 02:36:32 EST 2016

NAME

allocated for Ivan N. Ianakiev

Smallest m such that A267238(m) = n.

DATA

0, 1, 11, 2, 12, 112, 3, 13, 113, 23, 4, 14, 33, 24, 124, 5, 15, 115, 25, 125, 44, 6, 16, 116, 26, 45, 145, 36, 7, 17, 55, 27, 127, 255, 37, 137, 8, 18, 47, 28, 128, 247, 38, 57, 157, 9, 19, 119, 29, 67, 167, 39, 139, 457, 239, 49, 77, 68, 168, 277, 59, 159, 377, 259, 78, 178, 69, 169, 1169

OFFSET

0,3

MATHEMATICA

seq={0}; f[n_]:=Total[IntegerDigits[n]*(IntegerDigits[n]+1)/2]; lst=f/@Range[10^5];

Do[AppendTo[seq, First[Position[lst, m]]], {m, 1, 100}]; seq//Flatten

CROSSREFS

Cf. A267238.

KEYWORD

allocated

base,easy,nonn

AUTHOR

Ivan N. Ianakiev, Jan 13 2016

STATUS

approved

editing

#1 by Ivan N. Ianakiev at Wed Jan 13 02:36:32 EST 2016

NAME

allocated for Ivan N. Ianakiev

KEYWORD

allocated

STATUS

approved